Want to get rid of these anxiety triggers from my ex
Good to meet you, Nekta.
First of all, kudos to you for ending this toxic relationship. No one deserves to be treated the way you were. Narcissistic people do not love (you don't treat people you love like that). They just need to control, due to their own issues. So all you have lost is an illusion. That's why he moved on fast. You deserve much better than that.
I once left a couple of such relationships so have a fair idea of your pain. My heart goes out to you. In my case, it was a history of child abuse that led me to repeat the only pattern I knew.
Right now, you are grieving a loss. Even if you were unloved and unappreciated, you still feel pain and distress. Grief is a process that cannot be fast-forwarded. The fact that you got out of bed is progress...even if you need medication to help you over this difficult patch. But there is still some way to go before you can move on.
Are you seeing a counselor or therapist at the moment ? If not, I suggest you ask your prescribing doctor about going on a mental health plan, including subsidized therapist sessions. It would help you work on the reasons why you were overly dependent on such toxic relationship...and still are. Knowing the cause is the first step towards healing. No need to struggle with this alone. You deserve to reclaim some measure of control and peace of mind.
So please take good care of yourself and have an open, honest chat with a professional. With the right help and support, it can and will get better.