My 14 year old son

Hi. My name is Martin. I’m a 49 year old father of four boys. Who are 27, 21, 18, and 14. Conar, Ellis, Beau and Quaid. I split up with my kids mum the day before my youngest sons 2nd bday in 2005.  It was a mutual decision. The first 2-3 years after we split, I saw all my boys all the time. Then my Son Ellis decided he wanted to move in with me as he wasn’t getting on with his mum. And has lived with me ever since. He works with me too. And has a brilliant relationship with his mum now. Conar by now was 18-19 years old, living between his mums and mine.  He was working, and going out most weekends, and quite a lot of the time, I found myself out with him, and our relationship was really good. Beau now was 12-13 years old, and would come stay every other weekend, and come have dinner every Wednesday night. Without fail. We too have a good relationship. Quaid was now five and between me and his mum had detected there was something different about him, and decided to take him to see his doctor. After 18 months or so he was referred to see a specialist. And continued to do so every six months til he was 12. To which they eventually diagnosed him with having ADHD and Autism. During this time my contact with him got less and less, which was upsetting, but I had to get used to it. His mum has married now, and has a daughter of 7. Me and his mum fell out over his welfare in 2015. But in the last two months. We have started talking again, due too my sons welfare. She has told me she can’t cope with him anymore, and is at her witts end. Consequently in the last two months, I’ve seen Quaid more times than I did all last year. It’s also opened my eyes more to his condition. And I want to get more involved in his life. He is now on his school holidays. I’ve joined him to our local gym as it was something he said he wanted to do. But getting him to get up and out his bedroom to do anything has become a nightmare for his mum. Today I was rained of work. So decided to see if I could get him to come out with me. I phoned his mum to see if he was up. She said he wasn’t but I was welcome to go round and see if I could get him up and out. It was 11 o’clock. I entered his room to see if I could wake him. After a few minutes of calling him. He woke and told me too *** off. I had never witnessed this, but had been told of everything he does and says. I was shocked. He then went into a rage. Telling me he wishes I was dead, I mean nothing to him, and why am I bothering with him now!!  He then started to strangle himself telling me he wishes he was dead. I tried speaking to him more. But it was getting heated and I had to leave. I’ve now been crying most of the day. And don’t know what direction I need to go in. If anybody does read this and has an idea what I should do. Please get in contact.