Relationship issues 🥺

I have been dealing with this man for a year and I grew to love him. The issue is the whole thing is just super toxic and he had learned how to trigger me and cause me to get extremely angry. Just recently we both made a decision to just end it permanently and not even remain friends. I have just been so sick to my stomach everyday, sad, not wanting to be around people and I just want all of these feelings to go away so I can just get back to my happy self. I made an appointment to start seeing a therapist. I just don’t know what to do and I think about him constantly and it’s driving me insane ! Does anyone have any advice for me?