If you have identified that it's isolation you feel that's at the root cause of the jealousy, can you find ways or set goals to lessen it? Can you and t work on the anxiety so you feel in a better place to connect with others, maybe join a local group or start a course, even an online course? If you're unsatisfied with your life, the answer is to try and do things YOU find interesting to yourself, then it matters less what others do and think. Maybe find a subject you would love to learn more about and study it. Or start a blog on living with anxiety to help others. There are things you can do.

I second the idea to talk to t about your jealousy if it's a big problem. You don't even need to mention it's about her, just say you're jealous of others and want to work on it. A t should be there to help you so it makes me sad that you feel afraid to tell her things. I hope she will listen and be compassionate.