Feeling broken how do I calm my heart

I’ve dealing with this guy for two years now we went exclusive last year working towards a relationship. Go back to last year I found out he got his ex girl of 5 years pregnant. I was so devastated and hurt. I had a miscarriage around that time. Anywho his BM called a couple of weeks ago I noticed he had her pic saved as contact I called him and notice I was saved as my initials. I’m devastated and hurt why ?? Treat me like this. I feel lost and suicidal