In short I've been a developer for just over a year and a half now including my course time, I got assigned a pretty big project at work, something I'd consider a little bit past the scope of a junior to handle without supervision at least.  

I have someone checking up on whether I'm working or not but there's no one who actually understands the code I'm working with, or who'll take a minute to even try and understand.

Some of the things I've had to deal with are way above my scope in all honesty.

I was told at the start "You have until August of 2020 to finish". This was in November 2019, so of course I wasn't too worried.  

I spent the first 2 weeks trying every framework I could get my hands on, And ended up settling up with Xamarin because I'm most familiar with C#.

Now at the start I was struggling a lot; things just didn't work no matter what I tried. But one day my brain clicked and I started to understand almost everything. The only thing that I still can't seem to be able to work is IOS push notifications.

So obviously they kept checking up on me. Sometimes they'd ask crazy things and I'd do my best to implement them when possible.

At the end of November I had the bare-bones system working and showed my work to the CEO, when all of a sudden things went south. I started getting asked for updates twice a day, and if the response wasn't "it's done" I got these disappointed eyes and tone. I eventually decided to put a progress wall, having "Planning | In Progress | Testing | Done".
Lets say I had around 50 cards: 5 in Planning, 5 In Progress, 35 In Testing and 5 in Done and was told everyday "why is there so little in done", and whenever I'd try to explain that testing an e-commerce application on 2 devices does not mean it's going to work correctly when you have hundreds of orders going at once, I'd just be ignored.

Before we closed in December I got told they want it in February so already I was like "Okay, that's a huge push up from the old deadline" but just decided to push on.

During the holidays I was forced to work on a personal laptop due to the works Macs being too out of date for Visual Studio and the IT guy just never fetching my machine. My laptop broke a week ago. I started today and told my manager that it broke and I can't continue working on the application as I'd have to retrieve it from my laptop's drive which is under warranty so I'd need to send it to a repair centre. Now they are only open from 8am - 5pm m-f (my working hours) and it's an hour-long drive. Collection costs way more than I have at the moment, so I asked if there's something my company can do to help so that I can get back to working on as soon as possible, but just got ignored again.

Now about a 3 hours ago I got told that the CEO wants results and the clients want to see the app next week Monday, and I've in all honesty been made to feel like it's my fault the laptop broke (Note: I have no backups as they didn't want me to use Git and I have no external drives despite asking for them).

I'm not sure what to do. These deadlines are just getting pushed and there's nothing I can do. I was genuinely proud of what I achieved with the little experience I have; I've been working my butt off on this thing, having sleepless nights, but I'm getting it done. I just want to be given time. For instance, there are bugs where the app just crashes on random pages and I'm not getting time to resolve these kinds of things (not to mention I've been handed the company's website redesign, as they want it to be up to a top-10-CSS-websites-of-2020 kind of standard. The other developers have designers giving them things like animations, footage, icons etc. I have to do all this myself without any Photoshop experience.

Any advice? 

Adding on:

Firstly I want to say thank you to everyone for the extremely insightful responses; this is getting a lot of great answers so I feel like I should give a tiny bit more information as to my situation.

So this is my First "Real" Job and I've been working here since August, The money from this is keeping me and my girlfriend and our little one afloat. (I'm 25 and before now always just worked in small sales jobs, contract work, etc)

I've come to a kind of realize that it might be that I'm being given these projects instead of my manager so there might be tension because of that, The No-Git issue is that they do not want the project on the "Internet", (Please know I understand how silly this all sounds) as they fear I might leave and Use that application as an easy ticket into another company. Now I have yet to sign another contract after my probation so yes, there are more people coming to help, I have asked but have yet to hear, so apparently I just continue on the probation contract which I have not agreed to. The college I went to study at was more of a lecturer-gives-you-material-and-leaves-the-hall type arrangement, so I would say I'm self taught I lack any guidance, and with that I get to my main problem.

I want to be a developer people can acknowledge. I want to be proud of what I do, I want to understand the root of the problems of my applications, 
I want to learn Design Patterns,
Why things are the way they are, I don't want to understand Syntax on a 50/50 basis and just Google and repurpose, Not that there's anything wrong with that, I just want to work in stack and write Complex applications. I live for the thrill of figuring out something I never thought my brain could even comprehend.

In short, any and all request are denied, They've made it very apparent I can be replaced in a Week, So yes I do plan on finding a proper junior position In August when I have a year's experience. There is no mentoring, no senior to tell me that "Hey you know that run of 300 lines you just wrote lets cut that to 10 :)".

Essentially I can deal with the work amounts but I want to understand why it is this works, and why I would rather use something else.

Small note: the client is a million time's worse than anyone, they have hated everything I've done. They're never happy, and what breaks me is I never get told "it's crap" or "it's great". I'd prefer that, It's always "it's fine"; it's always a weird, middle answer

As for machine's at work The OS is out of date for Visual Studio and Xamarin as far as I know only functions on Visual Studio.

I just want to again say thank you to you all.