There are a lot of threads here on jealousy if you do a tag search. Mostly jealousy is about fear of something happening or someone threatening the status quo. If possible, flip it on its head and look at it from the other side. That is to see ones partner as happy and full of fun things in their life. Hard to do, but possible with practice. Break it down into the many emotions it usually is and explore each one. Walk through it slowly and deliberately because it likely will come up again in a different way if the issues aren't worked out the first go around.
Good luck. Everyting you mentioned in your post is common and people have woked through it. Keep at it.