Hi dovod,
I'm a comeback player, played in high school and college until I was 21, then pretty much didn't touch a horn again until recently, and I'm 49!
One big difference I've noticed is indeed in my confidence level. As a teenager I worried about my playing. Now, I worry about my job, my kids, everything else EXCEPT my playing. My playing is my escape. Consequently, I'm having a blast playing in a community band and a small dixieland band.
I had a band director in college who was fond of saying "If in doubt, play it out!". He knew (and I know now) that 95% of the people listening wouldn't know if you made a mistake, and 99.9% couldn't do what you're doing even if they knew you made a mistake.
Yes, heed the advise of getting a good teacher, et.al., but the main thing is: YOU gotta have fun at it.
Blast it out, man. You'll improve, don't worry 'bout it.
Steve