How should I handle my jealousy? Two friends of mine, that I introduced are now hanging out without me?

Hi, first off, I am not a native speaker, so my grammar may be not great.
I, (f 27), always struggled to make friends. Usually, I had one to three close friends, but a lot of time in my teenage years I spend without any. Even if I had friends, they were times, where I did not meet anybody outside school for weeks. Sometimes I even faked meetings friends, to get my parents of my back – meeting friends I did not have.
After I graduated, I finally managed to become part of an active friend group. It was great time, but after I spend two years working overseas and moving across the country for uni, I rarely see them. Finding new friends took me a while and I had a few intense depressive episodes.

So, three years later, I managed to have to established friendships (not the ones I am talking about in this post) and a bunch of people (or casual friends) I hang out with for activities, that mostly I plan. Why am I adding all of this, if it is not directly related to my current problem? Because of my previous experiences, a lot of hurt feelings and lost friends, I am very sensitive about this topic. I feel rejected extremely fast and struggle to communicate my feelings.

With the help of Bumble I managed to find a women (f, 24) I clicked with two years ago, who had just moved to our city. We hung out a lot and talked about almost everything. To be honest, I also had romantic feelings for her, but we never talked about that. After she (24) got to know more people she had a lot less time for me. Since she is rather active on social media, so I saw a lot of posts, about activities she did with others, I wasn’t invited to. Well… After some time, I also contacted her less and currently we see each other maybe every two months. I felt pretty shitty for a long time, but slowly accepted, that she is probably looking for other qualities in a friendship, I just don’t have. Sucks, but of course I don’t want anybody to force themselves, to hang out with me.

About six month ago, I met another woman (f, 30) and we quickly hit it off. She lived close to me, so it was easy to meet, even if we both were rather busy. Two months ago, I had a huge project for uni and she offered to help me, (Note: I didn’t ask her) and I was looking forward doing the project (something artsy/crafty) together. Well, when the date of submission came closer, she pretty much ghosted me for two weeks, because she had a hard time at work. Nothing I can’t understand, but after that it took her another three weeks to text me back. So, yeah, I did it without her and again felt crappy. Because of that and since I was not sure, how or what to write her, it took me about four weeks to text her a basic response.

So… two days ago, thanks to social media, I saw that these two friends (24 & 30) started hanging out. They met once at my birthday, but I wasn’t even aware that they got in contact. At first it was not that big of a deal, but I am slowly realising, that I am jealous of them. That they apparently found something in common and don’t want me to be a part of it. So… I guess it is pretty obvious, it hurts me. Well… I don’t want to be jealous and I don’t want that bruised of an ego… but frankly, I don’t know how to handle my feelings.
Anybody got advise? I have two other friends, I am close to and do lots of stuff with. My schedule is packed. It’s not the same as in my teenage years, when I had zero friends, but still… I feel so crappy. I miss them and the time we spend togehter. To be completely honest, I don’t want them to be friends. I want them to be friends with me…. well back to the topic, how would/should a normal human being handle themselves?