Microwave Door Twisted
Buy a new microwave.

It sounds like your microwave door is pretty cattywampus.
Microwaves are carefully engineered and undergo extensive testing to ensure radiation is kept in, and are typically not intended to be user serviceable.
Even a very small leak could have serious health consequences over time. Finally, if you are able to replace a door, you still don't have the equipment to verify that there are no leaks. In short: it's not worth the risk!