I (21F) need advice with my BF's (24M) girl friends

I have been with my boyfriend for almost 3 years (he is 3 years older). I love him and I've trusted him with things I've never trusted anyone with. Before him, I had never been in a healthy relationship, and he showed me what a good boyfriend should be like. At least I thought he did in the beginning.

However, there has been one ongoing issue in our relationship. He has a lot of friends, especially girl friends (but also many guy friends), while I don’t have any male friends at all and barely any friends in general. This has bothered me since the beginning, but I wasn’t comfortable bringing it up at that time, especially because he warned me about it since the beginning (the argument he keeps using in our fights). Now it has led to more arguments, and I’m honestly tired of fighting, so I try to push my feelings down instead.

One thing that really hurts is that we’ve never gone on vacation together, which I don't feel like is normal for the amount of time we've been together. I’ve asked many times for us to plan something, but he always says he needs to save money to buy a car, and that we can travel after that. However, now he’s gone on vacation with his girl best friend. They’ve been friends longer than we’ve been together, and they act like siblings, and are always teasing each other. I do trust them, I like her, and I’ve never felt the need to be suspicious of anything at all. It's more of a respect thing and lack of effort for me. He even tried for us to be best friends, because I am always telling him how sad I am about the fact that I don't have any friends. However, the situation makes me uncomfortable for a couple of reasons: 1. they are sleeping in the same room, which makes me feel weird because it feels like a lack of respect to me 2. he has gone on trips with friends during our relationship but never with me, and it feels like a back stab that he would go with her and not make that effort for us.... He says the reason is that she organized everything and that they’ve talked about this trip for years, but it still makes me feel shitty, and I feel like he doesn’t care to go on vacation with me or put in the effort, as if I’m not worth it.

Another issue is social media. He never ever posts stories about me, only reposts what I post about us. He also rarely takes pictures of me, which makes me really said and I've talked to him about it (he says it's because he likes to "live in the moment"). I even tested it out and stopped posting anything about us for more than 6 months, and during that time, we didn’t take any pictures and had nothing on social media at all. I confronted him about how upsetting this is for me, but he insists he’s just not the type of person who posts there. It may seem superficial, but these days and in our age, I feel like if you don't post, people either assume you broke up, or girls will talk about in your back about how your man doesn't really like you, etc.

I also have a highlight of our stories together so that men who follow me can see that I’m taken, but he doesn’t do the same. I told him I would remove mine then, but he said I shouldn’t because we’re different people and I post more, so it would be weird if I didn’t have one (but he can have none...).

What hurts even more is that during this trip with her, he’s already been posting stories of funny moments. I understand it’s a ski trip and falls can be funny, but it still stings.

When we talked about how uncomfortable this trip made me, I reversed the roles to get him to understand my point of view. He even admitted that if the roles were reversed, he wouldn’t like it either, but he said it was “different” because "some" men are disgusting, and also I’m not that type of person so it would be strange for me to suddenly do something like that (again I’m very reserved and don’t have many friends, so I understand but I feel like it's an insane double standard).

Do you think I'm acting immature? What can I do to make it better and stop fighting about it?

Lately, I've just been feeling so zoned out in our relationship (for many reasons, but the lack of effort is the main one), and I don't know how to fix it tbh.