I hope you find a good match! I used to have similar problems as you and got stuck for several years. This book has been life changing: https://www.amazon.com/Reclaim-Your-Life-Acceptance-Commitment/dp/1646112474/ (Not pushing anything, just my experience. It’s a science based approach, not quackery). What I understood is that I have to find my happiness (or at least contentment) as an individual first and foremost and improved relationships will follow. Not only with my husband, but people in general.
It really depends on you, the support you're getting, and what sort of techniques you're employing to help yourself cope and move on.
Have you been able to talk to friends/family about what you're going through? Are you in trauma-informed therapy? Are you practicing ACT or DBT? Do you utilize any grounding techniques? Have you tried scheduling your day to give yourself less free time to give into the urge to check up on him?
https://dialecticalbehaviortherapy.com/distress-tolerance/distracting-activities/
Are you able to see a trauma-informed therapist and get some help in managing these feelings?
You may also find these helpful:
https://www.talkspace.com/blog/gaslighting-in-relationships-signs-how-to-spot/
https://www.mindbodygreen.com/articles/what-to-do-when-youve-been-gaslighted
ACT and DBT techniques, as well as grounding techniques can help.
https://adoeci.com/sites/default/files/grupos/dbt-skills-workbook.pdf
https://www.healthline.com/health/grounding-techniques
Do you have a trauma-informed therapist you can work with on this?