Struggling with Intrusive Thoughts and Motivations

Back before my partner moved in with me during COVID, I used to be alone in my tiny studio apartment and wouldn't see anyone for days at a time. Honestly, there was a good number of times that I just didn't think I could do it anymore. I had never really seriously contemplated doing something like that, but, at the time, when those thoughts came, the thing that immediately drove them away was thinking about how I didn't want my younger brother to have to experience that loss and how my partner already had a tough life and didn't deserve to be the one to find me and be alone again. While I'm in a much better place now, I still get intrusive thoughts where I think like this and, oftentimes, when I think back on that time, I think that if I didn't have a younger brother or knew my partner, I probably wouldn't be here today. I was always slightly ashamed that, even now, I don't feel like I'm doing any of this for myself. I do it so they can be proud or happy. Should I want to live and succeed for myself or is it ok to do it for others?