Thearopy can be affective if you find the right kind of therapy and are willing to face things.
From what you have said, sexual abuse if not dealt with, can be a life long problem not only for you but also your children, my problems came from being raised by my mom who was full of hate and had major problems from being sexual abused by her dad, and it went ignored and still does, she has not changed and has always been a miserable person.
You said that your first husband was abusive, so that shows that you continued to choose people who be abusive, and from the feeling I get from your comments, your current situation if not physically abusive may be emotionally abusive, also added with your son having mental disorders that you also feel responsible for in some way if it is genetic.
Low self esteem, feeling that you deserve abuse, even if it is subconscience, feelings of guilt of self blame, and not being able to trust people, all quite common emotions for someone who has experienced abuse.
I am not a psychologist, but you need to learn how to face, deal, overcome the source of the problem, and you do need help to do that, its finding someone who really wants to help you and not just give you drugs and mask it, drugs can help but they don't remove past hurt, anger, abuse, that has to be dealt with.
I would not worry about what my inlaws think, don't worry about everyone else start focusing on yourself, you are worth it, you are important, you do deserve to be treated right, you do deserve to be happy, you are not crazy you are emotionally dramatized and scarred and need healing from within. I know there are refferences to psychogolist on this site, you know Dr Phil will reccomend the best, if its not near you they may can recommend someone who is, but it only works if your willing to allow it too, may be revisiting some things that are not pleasant, but there is light once again that which don't kill us makes us stronger, don't let the abusers in your past or even your present, continue to control and rule and ruin your life, fight for your happiness you do deserve it.