Basically how can I not lose the most important people in my life? And If I do can I life a happy life alone?

Hi everyone!! I’m going through a really hard time and I’m honestly terrified of losing the only two people I’ve ever truly loved: my boyfriend and my little brother. I had a really difficult childhood where I was never loved and was abused in every way possible. These two people are the only ones who ever showed me what real love feels like. My boyfriend found me during the worst period of my life and literally saved me, and my brother has always been my best friend and the reason I kept going. I love them more than anything, and I hope they still love me the same way. I don’t live with my brother anymore, and he’s only 10. I’m scared that as he grows up, he’ll forget me or that our bond will fade since we don’t see each other every day anymore. That thought alone hurts so much. At the same time, my boyfriend has been growing more distant. His replies are slower, more dry, and it feels like he’s pulling away. His vacation is almost over, and even though I was hoping we’d go on a date, it still hasn’t happened. I feel desperate and anxious all the time. I try really hard to keep both of them close. I’m always present, always texting, always checking in. I also spend my entire paycheck on gifts for both of them, literally my whole paycheck. If they want something, even if it’s really expensive, I’ll buy it, even if I end up with almost no money left. I just want them to feel loved and not leave me. But no matter what I do, I’m still terrified of losing them. I don’t know how to stop feeling this way or if I’m even doing the right thing. Does anyone have advice on how to deal with this fear of abandonment? And is there any way to make it through life alone, just in case I lose the only people I’ve ever loved? I’m really scared and don’t know what to do. Also is not that I only love them because I don't want to be alone. Any advice would mean a lot! Thank you :)