Alienation from children

Hi

I'm running out of hope. I had a severe bipolar manic episode in 2020. I was 48 and I had never had one before. I got increasingly bizarre and volatile until I went into psychosis. I was involuntarily hospitalised for 6 weeks and diagnosed. Since then I've been stable and managed to get my life back in order. The worst impact is that my two boys (now 9 and 11) don't want to see me. My ex and I separated in 2017 and she has custody. Custody arrangements are just by agreement between us - big mistake but too late now. I used to talk to the kids each day and have them over on weekends. I had no contact at all for six months after I got sick. Now I talk to them once a week and I've seen them twice in two-and-a-half years. I've tried apologising, I buy them gifts, I've tried everything I can think of but they just don't want to see me. I feel like they despise me. Counsellors etc just tell me to be patient, but that hasn't changed anything. Is there anything I can do? I'm getting increasingly bitter about this. It's blown my self-confidence to pieces. I'm going to try for mediation with my ex and then the Family Court to force the issue and spend time with them. I don't want to take that path but it's the last option. Has anyone else been through this? Any advice? Or is this just a consequence of mental illness that can't be healed? Honestly I wish I'd had a car accident, because people would have been sympathetic. But if you get psychosis then you can be pushed away for years, maybe forever.