Can anyone advise please?

I have recently had a nervous breakdown, brought on through financial and relationship worries. My daughter let my partner know that the hospital and doctors were involved and that it is serious and the crisis team were involved coming to my home daily and taking me to hospital support groups. My partner has not been to see me since, he says his son does not need to see me like this as he doesn’t understand and that the only time he has due to work commitments is weekends and he has to spend them with him. My partner left his second wife over 2 years ago and has a 9 year old son from the marriage. He has seen his son the majority of weekends Friday Saturday and Sunday since that time. When we met him having a son wasn’t a problem as I wasn’t the kind of person who craved going out, I was happy with once a month or so. Everything was wonderful, he spent most nights at my house and weekends I would either welcome his son into my home or we would stay at his house. We are both in our mid to late 40s and very much in love and agreed that we are soul mates, then he proposed. We agreed to move into my property and that in a year or so get married, sell up and by somewhere together. He purchased a mobile phone for his son who was then 8 years old, he rang most nights at least twice and my fiancé never mentioned I was with him as he felt guilty. Both his cousin and I mentioned that some weekend nights we should have a night out instead, and I pointed out that he shouldn’t feel bad as the majority of dad’s have their children one day a week in the daytime and that he was a fantastic father. He took this as me saying he should have him one day a week. I really do care about the little boy and I want to do the best for all of us, I don’t want to shut him out. His son stated that he only visits his dad to play with his friends who are local to the area where he rents and if he can’t do that then he won’t come and see him any longer. Since that time, I am allowed to his house occasionally at the weekend whilst his son is there, his son no longer visits or stays at my house and I see my partner once maybe twice a fortnight. He has called the engagement off and alienated me. He has a daughter who is 18 and hasn’t seen for over 10 years due to a row with her mother (his first wife) she lives hundreds of miles away. He says because of me he will lose his son if he doesn’t stay at his property and he isn’t prepared to lose another child. He says he is so torn between us. I have lots of concerns, we once sat watching Mr & Mrs when the child said how do you think we would do on that dad?... He most of the time sleeps in bed with his dad and his dad lets him go to bed at the same time. I have tried in the nicest possible way to say that he needs boundaries and I have tried to say that he is treating him like a wife, and allowing him to make the rules. I just don’t know what to do anymore. Debs Notts