I struggle to stay strong without splitting and getting as worse as possible

Lately I've been really aware of my behavior and decision making especially at intense mood swings yet i cant stop myself from the sudden switch in my brain and the constant black n white thinking
breaking down n psychosis-like symptoms became pretty common for me over the years especially after getting dumped on years long toxic teenage trauma
Since little age appeared as the shy quiet girl
N my coping skills were harmful towards myself in many ways., now imclean but long stuck on daily weed smoking n harmful substances., reality is crashing down and my rage and hopelessness is overwhelming to say the least
i need someone with mental health knowledge to suggest me how to get better coping skills with everyday intense emotions and breakdowns

Help appreciated<3