I am feeling extremely low and have started acting bitter unintentionally because he doesn’t care about me

I don’t get it I was the calmest and lovely person. Now I feel overwhelming rage and pain I have never been like this in my life , I burst into tears over a small issues . I still can’t process the situation that he does not care about me and lives the best of his life with someone new.Why is it so hard??

It feels like my body and mind keep expecting him to come back the next day, but he never does, and I lose control. Sometimes, I feel like I’m about to pass out, and my head feels blurry from all the pain and crying. It’s shattering to know that there’s nothing I can do.

I’ve been holding myself back from texting him for months, and while I’ve been trying to stay strong, it’s been incredibly difficult. I feel so bad. I struggle to communicate with others and can’t meet new people. I don’t even know how to behave anymore.

My self-esteem is very low, and I’ve even had thoughts of hurting myself.

I see unpleasant dreams and nightmares almost every night due to anxiety.