Umm...
Do you want reassurance or... something more, um, realistic? :(
I'm 46, my last (and best) "serious" band was when I was in my mid-30s. Looking back, we were "too old" then.
We didn't really understand what people 20-odd years younger us were into, most of us were too "secure" in the rest of our lives (the other three band members had mortgages, massive salaries), we didn't market ourselves to the right people, or, well, anybody really...
I'd already had the same sort of crises as you when I was 26/7 - and I accepted I wasn't getting anywhere, so I gave up playing to get married. It was only the collapse of that marriage that got me going with another band. I really thought we might get somewhere...
That last band nearly killed me, I ended up in casualty with "suicidal" written on the triage form, anti-depressants, and a rather tentative 4-5 years. I gave up music altogether for 3-4 years because of it, I just couldn't stand it, and removing music from my life is what saved me.
Music's music, and the music business is a business. You've got to be realistic:
Have you actually got something to sell? (I assume yes :D)
Is it something that enough people would actually want to spend their pocket money on? ( :?)
For you to make it, the people that might "pick you up and help you to go further", have to actually see and hear you, and then they have to be convinced that the answer to the second question is not "maybe", not "yes" even, but "HELL YESS!!". If they come on board, they are interested in you as well, but the reason they're doing it is to make money, not to dick-about losing money...
If you think that might still happen - keep going, I don't think there's anything to stop anyone any age from creating something that we all want... But you must put a lot more effort into finding out what the people who are spending actually want, and then into marketing yourself to the people who can help you into the arena.
But also consider this, this is age related as well, what are you trying to be at the moment? What is your self-image when you imagine yourself performing/etc? You're never again going to be that 18-22 year-old rocker at the peak of his virility/etc... At the moment I'm guessing you can still carry that off on stage, but another 5-10 years, possibly sooner, you won't be able to - you'll be approaching the age of "Dad" for your possible audience, and there's nothing you'll be able to do about it. You might need, already, to re-align the "you" you're trying to sell.
It's a real bummer... but that's what happens to us.
If I'd been on this forum in 1989 I could have posted your post, absolutely word for word. I really feel for you - and anyone else going through it. You've got the doubts already, you probably know the answer in your heart anyway.
My recommendation is "let it go", and concentrate on making and enjoying music... anything that happens after that is a bonus.
Sooner or later hanging on to an unfulfilled dream will do your head in.
Peace.