I would say theres no such thing as too young! SO don't worry about that. I don't have anyone who can lend me the money, nor could I get a bank loan, so I went to Uni and saved my student loan. I also got a good degree. ALthough you don't need a degree, having a wide range of skills and knowledge can be attained from haivng a degree. It also keeps your options opn.
ALso, I did computing science, and attained very little relevent knowedge relating to airline operations, however in terms of relevent skills, I learned a lot of new skills (ie team work, workload management, communication, leadership, how to learn a new technical skills effectively, as well as mentoring [a skill which could come in useful as a flight instructor]) but also skills which keep my options open. You get taught most of the operation knowledge you need during your ATPLs.
I would also say that three years may seem like a long time, but looking back, uiversity flew by, and was good fun, if a little intensive.