I have a few questions about weight loss

Alex
Well first off i am 16 years old and on january 1st i started my lifestyle change to become healthier to avoid becoming obese but according to my bmi i already was and that scared the crap out of me. January 1st i weighed approx 186lbs it is now april and i weigh 163lbs. I have made progress but i do not see it at all. 
So here are my questions 
Will i ever beable to tell a difference ? 
I have been chubby my whole life and my stomach is what bothers me the most and i guess what im trying to say is that i have a fear that it will never get smaller. Its all jiggly and it disgusts me. So will it always be jiggly no matter what I weigh? When is it a good tike to start toning my stomach? My goal weight is 120 oh and im 5"3 
I really just need some advice. Thanks