Please help me save my relationship.

My relationship is at a breaking point and we are desperately trying to hold it together, but we only have so many lives left. 🔹

I accept that a lot of it has to do with me, but there are two people in a relationship. Both with gifts and flaws. I have tried and tried to communicate and adjust and everything else I can think of to somehow stop our course to crashing and burning. 🔹

I don't have a lot of friends. They are mostly colleagues who I don't feel a true connection with. Not many close friends that I see from day to day. I'm an introvert. That being said, my SO is my best friend and the one person that I can see being in my life for a long time. 🔹

My SO has a lot of friends. And he goes out with them every weekend and makes time for them throughout the week. I am all for him spending time with them. I support it. But every time he does, something in me changes and it toxifies our relationship. I know that I'm jealous. But I have recognized it and improved so much from where i started. I realized that I needed to share him with the world. And I have. But nothing has changed from him, so I continue to feel the way that I do. 🔹

The thing that gets to me every time, is that I feel like when he's out drinking with his friends, I no longer exist. He won't text me or check in or do anything to make me feel like I'm even his girlfriend anymore. I WANT him to be able to hang out and get away from the world when he needs to. I just don't feel secure enough in my place in his life to not feel ignored or unimportant when he is out having fun without me. He knows this. But nothing has changed.  🔹 

I know that this insecurity has developed over time. When we are together, everything is fine. But when we are a part for more than a day, he disappears. No phone calls, minimal texts. It's like I no longer exist. And it has hurt me and he knows this. And says he will do better. But nothing has changed. 🔹

I have recognized that I need more validation and attention from him than he is used to giving. And I have changed for him, tried to adjust. I no longer initiate sex because I recognize that I want it every day and he only wants it one day of the week. It made him feel pressured so I stopped. I try to put his feelings above my own. 🔹

I feel like I am putting 110% of myself into this relationship. I have made conscious decisions to change the way I think and the way I feel. I have molded myself around his wants and his feelings. Why do I feel like I am the problem? I feel like I am poisoning this relationship. Yet I know deep down that it is NOT only me. I have recognized my flaws and have made efforts to change for my relationship. I just feel that it's a one-way street and that in doing so, I have branded myself as the problem. And he uses that every time we fight. And I don't know what else to do. 🔹 

Thank you to anyone who took the time to read this. I really appreciate it and any advice you have to share with me.