You need to have a life of your own and he is way too controlling. You have not done anything to not deserve his trust.

the whole thing with the password is just weird. you are his wife, you have his baby, he can't share the password? my ex and I knew each others' passwords. We never used them without permission, but we knew what they were.

tell him that you are going to start taking one afternoon a week or one morning just for yourself and he needs to let you have that freedom. And when you get your own computer (start saving up for it) keep your own password for yourself. If he doesn't like it, too bad. If he has his secrets, you will have yours.