On moral grounds, you should be taking care of your second wife instead of searching all her medical statements to prove that she had cheated on you. You should be supporting her on medical treatment. What you will do with her today she is going to do the same thing with you tomorrow. Noone remains young and healthy for the whole life and at the end of days, everyone need a life-partner who loves her from bottom of his/her heart... She has NOT cheated on you but she had believed that she could be able to accommodate with you with ongoing disease without having any issues. Even when the law says that it's acceptable then why you had so much issue in living with her peacefully. As you said that you haven't got any money from her, so technically speaking, you got dowry from your first wife and then what happened?
As far as the household work is concerned, you can engage some maid to do the same. She is not leaving you and that is so much honest response from this lady. She is trying her best to adjust with you and you should help her to adjust with you. You have to understand that you choose her to be better half of your life, you can't give-up on her just because she could not do some household work. If your preference was to get a better half of your life, who could do your household work then you would have married to a maid. Would that be acceptable for you?
Female are NOT object to be consumed and throw away. Your first marriage could be your ill-fated destiny but your second wife is your future, leaving her on this way would only give you more suffering in future.
As far as your parents are concern, let me ask you one thing. If you get away from second wife and then further not able to find a good bride for yourself then how your parents are going to support you and themselves? Today, cities life are fast and people should respect each other to come out from any situation.
As brotherly advice, stop thinking about negative things and focus more on future and positive things. Things are going to change one day but you have to be little more patient. Until and unless you are going to stop thinking that she had cheated on you, you won't able to respect your wife. Your wife didn't cheat on you; it's just purely coming out from your mind that she didn't tell you something so she had cheated on you. Do what helps each and everyone in your family. Do it for the sake of family not just in fear of police & court!
All the best and have a good life ahead!