Don't get discouraged. I know someone that was invited for six medical school interviews and was accepted to their first choice. This individual also did not have a high school diploma, but a GED. What matters is where you are headed and that you have clearly defined reasons why you are headed there. Pray. Believe in the person the Lord has made you to be. Take it one semester at a time, the confidence will come.
Gosh 25 is just a baby compared to some of us! There's a gal on oldpremeds.net whose screen name is GED2MD. She is either a surgical resident, or a practicing surgeon (I can't remember for sure). Anyway, she's done it and has interesting things to say. Check out her posts, send her an email, whatever you want...It CAN be done and she will encourage you!
I asked the same question on the OldPreMeds site. I, too, have a GED. You bet it is possible. There are several inspiring stories on that site. Including a man who learned to read at 25 and is now finishing his residency and ofcourse GED2MD! I believe the current trend in ADCOMs is to find well rounded individuals. Folks who have life experience. My story is far from traditional. As, I am certain yours is too. You can do it... just focus on one task at a time.