I am sorry you are hurting.
Could reading about poly hell
What about page 5 and 6 of jealousy?
Or more jealousy?
Maybe those could help you figure out how to cope with the emotional management side of things? Could your partner be willing to read those with you?
If you are military, you prob have PTSD help to hand -- check in with your counseling resources. You don't necessarily have to talk about poly if you do not want to, but get the coping skills for PTSD flare ups. The triggers can be X, but the coping with coming down after getting cranked up -- that could be the same techniques regardless of trigger.