If your partner is affecting you this much long terms then maybe you should see if you can find a way to cope and if you can’t then you might be better off splitting. I find it quite harsh and disrespectful that you’re blaming his depression when you’ve had countless people advice you getting therapy for your personal trauma and issues.
If you’re struggling with depression then you should really see a therapist, also for your severe overthinking and self sabotaging behaviour.