Have you explained to him that if he does not see a doctor and start getting better you can’t stay with him? Perhaps you and the kids could go and stay away for a week or just a weekend initially, tell him you need a break. Perhaps that will kick him into action.
If you can get yourself some therapy now before you feel any worse that would probably be good for you. You are doing the right thing by being aware of your triggers and looking after yourself. He may be kind and caring but if he doesn’t take your advice about getting help when he knows that it’s having an impact on your health that’s not great. Doctors have heard everything, loads of people have sexual issues when they are unwell.
Whatever happens it may not be forever, as long as you and the kids are ok then you can work on things with him when he gets better. You’ve loved him before as a partner and you might do again once he’s able to be a partner to you