Hi and welcome! I think you've already got quite a bit of understanding regarding your own jealousy. It seems you've already perceived that it comes up when other issues are present as well, or when you're feeling vulnerable. When I've felt jealous, I ask myself, "Okay, what is it specifically that am I actually jealous about?" And I keep digging deeper and deeper, because I think that jealousy is always there over top of other feelings. And if you deal with those feelings, it helps dissipate the jealousy. So, maybe when you're in "emotional turmoil," as you put it, that would be a good time to occupy yourself with activities you enjoy or hang with people whose company makes you feel good about yourself, and not dwell on what she's doing. Easier said than done, of course, but I'm sure as you keep getting to know yourself and your own thought processes, you will find a way to handle it.
The world opens up... when you do.
Oh, oh, can't you see? Love is the drug for me. ~Bryan Ferry
"Love is that condition in which another person's happiness is essential to your own." ~Robert Heinlein