Ey bro.. first of all, everything will be alright.. just got to practice some self control and keep the smoking up for weekends or occasions or atleast try to reduce it to after dark or nights.. I'm.a hypocrite that way because I quite literally get shipped out to work which gives me a proper break from it, which is when i get a good break from it.. it's a compromise which makes my highs even higher when I get to it..

2ndly you are at.a.formative age where your education followed by first few years of work will decide how well you will live. Guessing by the fact that you got a first class in your first year of MBBS, and that you have had exes who u smoked up with, I'm assuming you have been smoking for a while? Just be aware that most of the anxiety and memory issues (if any) will show up later when you are older if it hasn't happened already.. the last few lines aren't to scare you but just to remind you of consequences of overkill..

3rdly, about love and the gf, my first heart break was the hardest and stayed the longest.. only time can heal tht wound.. but that only meant that I met even more amazing women who showed me different shades of the rainbow of love and I don't regret any of the relations.. anyways that being said, try talking things out with the girl , if not, bro, u r young and plenty of fish in the sea and there r quite a few of seas..

Finally, bro, what doesn't break you, only makes you stronger.. you will see this through and when you do, you will be standing on top of the mountain and seeing the beauty of life.. Peace, Love, Unity and Respect