How do I become okay with aging when I only see only misery ahead of me

I'm 33 and for the past 8 years my life has felt like it's in a state of transition. despite that, I don't really know what my life is transitioning to, or if I'm already there and this is just what it's going to be like fo the rest of my existence

I see my body aging and realize I no longer recognize my decaying body in the mirror. I see my friends getting married and realize that they're drifting away from me and I'm soon going to be on my own. I see my parents aging and realize that I might outlive them sooner than I thought I would. I see the world rotting from both ends, and can't help but feel that decline is an inevitability: that my future will never again feature the grand highs that made me genuinely excited to be alive

I know I need to learn to be okay with seeing myself grow older, but I don't know how when I can't percieve a single upside to all this. Maybe I shouldn't try and predict the future, but it's not like I'm going to get younger. It just feels... hopeless