My dark cloud

I’m new here.. I need to vent. I feel like everyone close to me has heard it all soo many times that they no longer have any empathy or a desire to lend an ear. The problem I’m enduring is an ongoing mental health issue with my partner.
Some background information.. we have been together for just over 5 years. When we met it was like a normal “getting to know ya” conversations. We met online and then discovered during our first in person meeting that we had in fact been introduced a few years prior by a pair of mutual friends. However neither of us were single at the time, it was simply a friendly hello my name is .. a handshake and a wave and nothing more. Flash forward almost 4 years and now we’re having ice cream on a date. My life had changed and I was going through a divorce but it was clean. Amicable. No court no lawyers. We were able to come up with a reasonable shared access custody arrangement and a fair (table amount was referenced) child support amount to be paid monthly. My relationship with my new partner was slowly evolving into something bigger and stronger. Or so I felt.
I knew my partner  had a child from a previous relationship. This was never an issue as I too have children. However it was the obsession with the access and time spent with this child I found alarming. Constant anxiety until the child arrived on Friday and then all was well until Sunday night when they departed. More anxiety. I didn’t understand. It was shortly into our relationship that my partner was served family court papers. Things have escalated since.  There is no help here. I’ve been burdened with my partner’s  grief and constant urge to end it all. I’ve even taken them to the hospital for assessment. The guilt I’m feeling of holding onto this constant dark energy is draining. Being told to leave and walk away is not such an easy task otherwise I would have taken that path early on. I have hung onto hope that everything would work out until recently. I’m losing my grip on my own mental state. I can’t keep this ship above water without some support. I go to work just to escape.