I do much of what you mentioned when I feel jealous. Why do I feel this way? Is is solely within me? Is it something I am percieving or is the situation actually a problem? Is there something that has triggered an insecurity of mine (yes 98.9% of the time)? Is there something that my SO is doing differently that has triggered it? If so, is it something I can adapt to or does it conflict with my beliefs?
There have been times it is something I have totally misunderstood. Sometimes I have to ask myself where the heck I came up with that perception. Sometimes, I've had to ask for some help form my SO. It makes me feel X when you do Y.
Then there have been times I've discovered it is envy more than jealousy. Say that Gator and I have for years made time for a date once a week. Now that he has Kitten in his life, we aren't able to fit one in once a week but try for once evey two weeks. Ok, this works. But then say life just keeps getting in the way of those date of ours and we never seem to be able to have one. However, life doesn't hit the relationship he has with Kitten as hardly and doesn't interfere with their date nights. I'm not jealous that he is having them with her but I miss the ones we should be having and I envy the time she is getting with him. I have to talk with him and we both have to agree not to let that life interfer as much and for us to get the much needed bonding time as well. Here, I can be happy he is getting his time with Kitten but unhappy our time together has been delayed. It can come out hurt and irritable as jealousy would but that isn't what I am feeling. I had to analyze first and then go from there.
Sorry to ramble.