First let me say I wish u no disrespect, but whirlygig hit it right on the head. High intensity sim and line training are a young mans game. I'm talking 121 style training where pressure is always there. I did my last type (MD-11) at 46 and damned near did me in.
I was a check airman my last 15 years and knew if my next trainee was 40+ (f/o) it was going to be a sh@tload of work for me, if 50+ and capt. trainee really a sh@tload of work.
Read that book of the 100 greatest people of all time and you will find the vast majority of discovery was in their 20s.
Don't mean to rain on your parade and you can do it if given the chance but you will need to be more dedicated and motivated.