@sillywh1sp4r
At what point does the game go into an infinite load screen? From what you said, it sounds like you can get to the map screen and go into a lot in build mode. Is that correct?
Can you go into Manage Households and take sims to CAS? Can you go to CAS to edit existing households, and can you go directly into CAS to create a new household?
Do you now or have you ever had mods and CC?
What I am thinking is that you may have one or more corrupted sims in one of your households. Or it could be broken CC or mods. Some broken mods will send the game into an unending load screen or simply cause the game to not start or crash. And a broken CC item can corrupt a sim as well.
Hope this helps.