I'm at a loss for advice to give on your situation. I'll definitely be following this thread, though. I had never considered the compounded inner trouble potentially brought on by the stack of insecurity+jealousy+competitive nature with a friend
to whom your love is showing interest.
One thing I know as fact is that our journeys tend to make us bigger and better people in the long term. The sum of poly existence for me is "Big feelings, Big bruises, Bigger rewards." That being said, the torture of being in the blood and guts of the sometimes trying present isn't easily soothed by promises of a happy future.
Big hugs for you though. I'm sure someone has some good advice and they'll no doubt be along shortly.
Best of everything to all of you,