Problem is you gave up. I had people tell me I was too young to become a service manager for a automotive shop, didnt stop me from trying. I called every dealership in the phone book and found a place that gave me a shot as the night manger. Dont let people tell you you can't or even yourself. Just keep trying, make calls, make follow up calls, make follow up calls to your follow up calls and keep calling till they call the cops on you for harassment. Sooner or later one will go "This fvcking kids got determination lets give him a shot, plus I am sick of him fvcking calling me."
Oh and fvck the newspaper classified adds. I cant tell you how many jobs I got pulling out the phone book making cold calls. Just call and be honest with them. "Sorry to bother you, Im calling actually from the phone book in hopes you may be hiring."
I have gotten several jobs from people who said "How did you know I was looking for help" or "I was just about to run a ad, can you come in today." It never hurts to try it and since it is the phone book its listed right there all the jobs you could want in your field in alphabetical order, start with the first one and work your way down the list making notes on the side.