What is the point in taking care of myself?

Title.

I have no friends. I lost them all today. I made that choice myself. I broke up with my partner (all of the pressure was on me with our relationship and I couldn't handle it) and I told my friends that I didn't want them to choose sides, so I'd be removing myself from the group.

I don't have anyone left. What is the point in looking after myself anymore? I only took care of myself for my ex. I never imagined myself growing up past, like, 25, for any other reason than marriage, but now I don't have that goal. So what's the point in continuing?