well, you're not stupid...
i try hard not to think about these thigns too because it scares me as well... i am younger than you but i keep realizing that im 26... in 4 years ill be 30... and this is like... i just can't see what has happened to my life...
its scary... i dont think its irrational...
it makes me want to cry because like you i wanted to be in a committed relationship by now... be able to take care of my parents and take care of myself...
but i can't even take care of myself currently... and i think that seeing these years pass by makes me feel like what if i am never able to achieve those things...

my old therapist told me that i have to stop using should statements... stop thinking about the what ifs.... but its easier said than done...

i think what we should try to do though is to accept these things... our age...
the more we try to fight it, the older we get, and the harder it gets to accept that we are really that far in life...

i dont really have good advice about this... i just wanted to let you know that you're not alone in this at all - alot of people struggle with these feelings...
and it is scary... i still feel like i am 17 sometimes... besides all the aches and pains i have from being so wreckless and stupid in my short life...

i hope that an internet hug will help a little...
happy early birthday... try to do something nice for yourself...