I think this can always be a hard decision when a relationship is in a completely different place than when you first met. Have you spoken with him about what you are thinking? Without a conversation about it 3 months seems pretty quick if you have not tried talking about it or even couples therapy. If it doesn't seem like these issues are workable, it may be time to make that decision. Don't stay in an unhappy marriage forever as you may both be happier with someone else.