Hi @Boymum2 , I hope its OK to respond to your post - but feel free to disregard if my perspective/thoughts are not helpful or wanted. 🙂
I am not a parent, so I cannot speak as a parent.
However I was/am a child who had had struggles with suicidal thoughts and desires since I was your son's age. I can say that I often did feel sorry for my mum as even though she never expressed to me her worry, I knew she cared and that it would naturally have worried her to know. Thankfully she was smart like it sounds you also have been and got me psychological help as soon as she was aware of it. 🙂
In terms of how to cope, again I cant speak as a parent, but I can speak as to what my mother and I set up for my safety and her sanity (worry).
I really appreciated that she didnt "check in" on if I was coping every day - but she would naturally always ask how my day was (as she also would my sister). This gave an opportunity to talk if I had a bad day or wanted a hug or to talk.
Her openness to talk or to "just sit without talking" or to help by providing a distraction (play a game, watch tv together, go out for a hot chocolate, etc) was really helpful and valuable. It also helped me feel safe and OK to tell her if I was having "difficult thoughts" even if I didnt want to talk about them with her.
Knowing that I could, and would, reach out to her if I felt really intense urges I think helped her to know that I would be physically safe (even at times I was emotionally distressed). She also set me up with another trusted adult who became like a faux-parent mentor too who I could always message or call if I wanted to instead. This gave another safety-net.
If I was out late at night (as I got older and independent as a young adult but living at home still), we had an agreement that I would message her if I was staying out late, and also message when I was leaving and returning home. This was also generally good safety in case of an accident. 🙂
This worked really well to help her not be worried, except for one time I remember because my mobile phone battery went flat without me realising! And it wasn't until 5am that I realised and plugged it into my car to charge. Then I found all these missed called and messages from my poor worried mum! I called her back ASAP to let her know I was OK and just chatting all night to a friend and lost track of time and battery.
I never realised just how much she still worried at that time (despite 8 years of managing the thoughts) if I was unexpectedly non-corresponding, until that incident. After that I always made sure to check my phone battery and let her know if i would be later than expected.
I think trust and an agreement that I would always reach out to *someone* when I felt that way were the key things for us. For me if I promise someone something, I keep that promise. That may or may not work for your son - but if they have something like that that you can leverage as an "assurance" that might help??
Openness with my mother about how she felt about wanting me to live was important. Knowing that she would prefer for me to still be alive even if I was financially dependent on her and needing home-help, rather than to cease to exist because if I wasnt able to cope independently - that has always been such a huge protective factor for me, even still. Knowing that is her preference if I were in that situation, and the acceptance that it would still be OK with her.
I hope this insight from my perspective may help in thoughts on how you may be able to find ways to cope with the worry for your son and build a close supportive relationship that encourages him to reach out openly if he is having those thoughts. ❤️🩹
Feel free to tag me if you have any questions or would like any other insights from my perspective as "that child".