I can't connect to my servers SQL database via an IP Address
Your SQL Server is installed as named instance, so first of all try connecting to your server using the following server name: IP Address\SQLEXPRESS. 
When you install SQL Server as named instance it uses dynamic TCP/IP ports by default, so it is not possible to connect to it whitout specifying instance name (just IP address). If you need to connect to your server without using instance name you have to reconfigure your server to use static TCP port. To do it please perform the following:


open SQL Server Configuration Manager;
switch to the SQL Server Network Configuration | Protocols for SQLEXPRESS;
double-click the TCP/IP protocol;
select the Yes value in the Enabled field;
switch to the IP Addresses tab; 
find the IPAll section;
clear the TCP Dynamic Ports field in that section;
specify the 1433 value in the TCP Port field:

restart your server
Try to connect to your server using just its IP address.