How do I reassure my partner who has low self-worth?

My girlfriend and I (both 21F) have been together for nearly over a year now. We truly have a loving and fulfilling relationship, and I am so lucky to have met her. When we want to confront each other with something that is bothering us we normally are very open about it and are able to get through it together and come to a resolution. But there’s been a recurring issue in our relationship which I do not know how to solve.

For context, My gf has been open about her struggles with low self-worth – which leads to her insecurities with her body, her social skills and intelligence. She believes something is fundamentally wrong with her, but this isn’t true. I am patient with her, and I truly do not mind reassuring her and being there for her because I love her and I know that she cannot control how she feels about herself. Sometimes she doesn’t really process my compliments and reassurance, but when she does she tells me she’s sincerely grateful for it.

Last night, I went to spend time with my friends – nothing relating to drinking or anything that would cause concern. I updated my gf on where I was the best I could. I came back pretty late and we get on Facetime. At first the conversation was moving smoothly, I was telling her about my day and what my friends and I did. The more I got into detail, the more distant and cold she became with me. This isn’t the first time she’s acted like this after I spent time with my friends. I was facilitating most of the conversation, and she made it apparent in her body language that she didn’t want to talk to me. I asked her if there was anything wrong or anything she wanted to talk about, and she said she would talk about it the next day, and reassured that it wasn’t about me. We ended the call (she took me being tired as an out and said goodnight briefly before ending the call).

I ended up calling her back again as we both were still up. She had told me that she had been feeling jealous of me, and that she knows it’s not the best thing to feel but she can’t control it. She stated that even though she’s happy for me and doesn’t feel entitled, she feels envious of the fact that I seem to do exciting activities with my friends, and that she doesn’t have those experiences. She feels hurt because she says that she doesn’t have an active social life, so she gets jealous. She further told me how this ties in to her insecurities and her low self-esteem. She even went to beat herself up and say that I deserved someone who was happy for her and that we were too different and she cannot bear to feel as hurt and doesn’t want to act cold towards me.

I reassured her, stating that I love her and love spending time with her and that certain activities we do together are special cause we’re doing it together, Which she appreciated. But I don’t know if that’s enough. I feel like I have tried many things but I’d like to know what else I could do, any advice is greatly appreciated.

TLDR: gf has been feeling jealous of my social life, which ties into to her low self esteem and insecurities. She doesn’t want to feel this way but she does. Even though I reassure and support her, she has a hard time processing the compliments and often feels I deserve someone better. We normally communicates openly about issues we have, but this a recurring problem and idk what to do.