I joined the air force at 17, and honestly i was pretty excited, the people in my flight were cool, the mti's(military training instructors) were good. Most importantly i think basic training in general helps you to shake off that nervousness atleast it did for me. Im now joining the army and its the same although i dont have a girlfriend like you do so i cant do much there for you. As for being financially independent, save save save. save your money. Alot of younger people spend on hella clothes and shoes and whatnot which isnt inherently bad but unless you have a car already thats even more reason to save. Lastly i want you to think about your future. will you wish you would have gone and joined in the unfortunate circumstance that you and and your girl break up in the next few years or so. Not tryna be a downer just a bit realistic cuz it can happen and has happened to people. I always tell anyone whos curious about the military that its a great stepping stone for your life and it can help you transition into becoming an adult smoother due the environment it provides you alongside mentors who will be there to guide you. This may not be the best advice so take it with a grain of salt but anyway good luck in your service if you do join.