Hello Friend, Good that you are seeking a help here. Your history clearly shows, you are still carrying perception about ex love and impact of that love. Your anxiety and negativity are symptoms of those underlying emotional stress.
If you wish your new relationship for long term, then it's better to come out of your past by to accepting the facts than trying to tolerate or forget the memories or creating perception.
Suggest you to get yourself assesed for a complete mental health once again from a psychologists. Post that you can follow few lifestyle routines, self therapies, excersise to overcome this anxiety issue.
Next Steps
Feel free to reach out to me online through Practo app for further detailed evaluation and suitable recommendation. Be positive. You will be alright soon.