Alex, I'm not you, I'm not in your shoes, and so feel free to take this with a grain of salt, but I would enlist with a good AFSC, be the best in that field, and work on your language abilities. The Air Force Operations fields 1xxxxx are almost always undermanned and almost every field is open to a first-term airman for cross training. I don't think TACP's were ever closed to cross training in the history of the AF. The AF is also down-sizing so available jobs will ebb and flow.
You seem like your heart's in the right place, but your head needs to catch up. I am NOT saying you're stupid or dumb, but TACP is a career field where your communication skills are very important. My logic is that if your written and spoken English needs some work and your ASVAB scores are a bit low, you will benefit from a few years in uniform before crosstraining. Go in, work on your 5 level, work towards your CCAF (this may make sense later but not now), and retake the ASVAB later.
Your only other option is to work on your own and hope to improve enough to enlist with a TACP slot. I'm just a contractor but I see the premium the AF places on education, so opportunities to improve abound in that branch. Also, a few years in uniform allows any citizenship/ clearance issues to work over time. You're young and time is on your side.
Your life, your call, but I think a short-term "disappointment" sets you up for long-term success. Be the best in your AFSC, work on PT, improve your language skills, stay out of trouble*, and crosstrain. That careerfield will be there in 2-3 years.
Good luck with whatever path you choose.
* - The easiest ways to hose yourself are drinking, debt, and just being a dumb kid in uniform. Don't fall into those traps.