Figuring out your Career?

How exactly do you figure out what you want do for the rest of your life? I am currently going through a moment during my life where I feel like I need a career change. I currently possess a 2 year degree in Criminal Justice. I am 3 classes away from my bachelor's degree in Forensic Science. When I was 19 I started this career... I am now 23 and some things although change... I enjoy recreational marijuana and it helps me to relieve stress and uncertainty as well as anxiety.

Usually a person would figure out there career by there hobbies and interests. I have thought of ideal subjects for careers but only involving medical science and technology. (That's my passion so far which is to enter the medical field someday).

Can anyone spare some advice on how to choose a career you would enjoy and how to obtain something that would be a great steady paying stable opportunity without years of schooling... How do I figure out a career for the rest of my life?

Thank you.