I love my life but I don't know how else to cope with my feelings

I have a completely normal life filled with people who love me and I work a job I love and have a life I enjoy living but everyday I want to cause myself physical pain and I don't know how to stop.

I feel pretty awful about the fact much of this is related to seeing an abusive ex boyfriend again in public. I left over a year ago and most of the abuse was emotional/verbal although very intense and there was a lot of vague threats against my physical safety and potentially some grey area bad sexual situations he never physically hurt me or directly said "I'm going to hurt/kill you" so it feels pretty pathetic the way that this seems to be retraumatizing me in this way when many in worse situations cope better than me.

I have been on and off harming myself since my mid teens, when I was 18 it got really bad but I was generally doing okay until I ended up in this abusive relationship when I was 19, I turned to hurting myself to cope with the stress of how my ex was treating me and when he found out he started injuring himself in front of me to scare and threaten me and consistently brought it up as something that made him greatly lose respect for me.

I have a wonderful and incredibly kind boyfriend now who does not abuse me and is always there for me but I struggle to open up about this kind of thing and I know it would make him worry for me more than he has to. He called me recently so I'd have someone there after I told him I was doing very badly after seeing my ex boyfriend in public (which I only told him after he asked to make sure I was okay since he was there too, I almost told him not to talk to me because I hate telling other people about how I'm feeling) and when I told him I was struggling with the urge to hurt myself he went very quiet and serious about it. I don't want to make him worry about me like that.

The concern for other people does not stop me, it just stops me from doing stuff that's more taboo or typically associated with self harm to hurt myself and means I instead do stuff that's faster and more normalised but I'm scared that what I'm doing instead is going to cause me concussion or nerve damage.

Almost every small thing that stresses me out if I'm in a bad mood makes me want to have a meltdown or injure myself, I have a job that I love but it can be really stressful at times. I have a loving family and a loving boyfriend (not very many friends though) I have enough disposable income to do fun stuff in my free time and I go out semi frequently and I talk to plenty of people through my work about stuff I care about, I have so much to give me a sense of fulfilment and use in this world but I still just don't have an outlet for negative emotions other than causing myself pain so I can feel the physical pain and the dopamine from that instead of my usual intense negative emotions and I don't know what to do.

I'm also planning on going on a new medication soon (I'm not on any meds currently) that could severely worsen my mental health judging by my family history and I'm just not sure how to get my act together even though I know that most of my emotions are entirely irrational. I just don't know how to stop wanting to hurt myself. How do I make the urges go away? I don't know what to do