definitely not too old
consider simply this
some people who die at 50-60 live incredibly productive lives
One of my heroes, Wolfgang Pauli died before 60.
Assuming you live to 70, maybe 80 (can be done just gotta take care of yourself), you could easily have more productive time after college than he did, even with your late start
best of luck to you. remember, things can make it more difficult for you, but I don't think anything can stop you
G.E.D. shouldn't even be too hard, from this post I can tell that you have the maturity to handle it.
I suggest going to a community college for liberal arts or general studies if you have no idea what you wanna do. It's a good chance to explore many subjects and get a degree for cheap
anyway gl