Would it be weird of me to send friend requests to old friends I knew in school 15 years ago?

I'm female and 30. Long story short I've been feeling very lonely and depressed lately, I've also lost a lot of time due to health problems so my life kind of paused soon after I finished highschool. I keep thinking of warmer memories and I keep getting sentimental over old friends especially because right now I don't have any real life friends to turn to because everyone parted ways and I was bedbound for many years.