How old is to old to decide on kids?

So background on me, I have extreme anxiety and depression from a young age. My mental health has affected my life greatly to the point where I havent been able to live my life normally. It's gotten a lot better as years have gone by but it's still really hard.

I am in my 20s and not sure if I want kids yet. I have never had a successful relationship and I feel super pressured because it seems like everyone I knew from high school are having kids, are engaged, etc and I feel left out.

But I'm still not sure if I want kids at all. I'm scared I'm too selfish of a person to put all my time in raising one, plus that and my mental health issues are not a good mix. I'm afraid I would give my kids my mental problems.

Women have a biological clock and I dont want it to be too late before I decide. Does anyone else have this problem?