Welcome, Welcome! and as CodeJob said-- wow, after 4 months and many of us are working on many years.
You are a mighty strong as far as I'm concerned, and you have a great head on your shoulders. Don't Panic, whatever you do. Don't feel rushed to make a decision either. Think this through and make a plan.
I see your concerns and feel you are just as hurt because of feeling/being lied to.
Can you get the money from the account and put it into yours alone? Is the money in account of his name only? You mentioned you needed to demand the passwords.
Hang in there and here as a matter of fact. These people are amazing and will be there for you all the way, no matter what you do.