First of all, you are not old. Im 41 years old and I'm in my 3rd year of medical school, by the time I'll have my office and I'll be working as a "doctor" I'll be around 46-47.
YOU ARE NEVER TOO OLD To STUDY.
Think of it this way.... Sit on your favorite chair, put you feet on the desk or table, hands behind your head.... now relax and Close your eyes, think that now you are 30 years old and that you have gone to college and finish school, now you are a professional....feels great right? Now do the same, close your eyes and think you are 30 but no college....it does not feel that great right? The thing is you are gonna get old regardless of what you do, so you are gonna turn 30 whether you cry, dance, sleep or smoke pot everyday. So you might as well get a degree as you get older.
Good luck.