Bhai,
70% in plus 2 not much high score it does not mean i am trying to discourage you...
You have GC and still teenager , you will qualify for financial aid
Go college, focus get A+ on basic science/math
3/4 years you will have a degree
Then you will have a platform can run business or further professional study (doctor/lawer whaterver) or can do IT...
short route , If you really enjoy in medical field go back nepal and study in private college(if you have enough money) keep coming once a year so gc does not expire
After MBBS you can try for residency
To become medical practitioner in usa is not that easy too, long process and no work life balance too
Do not depress /confuse stay focus on exactly what you like ? do not bump around gas station, grocery store ..
Good Luck