Yes Sameer, all these drugs and medications are useless and with strong side effects.
Only exercise,and i mean mostly cardio exercise, can have a true and only positive effect on us and our mood.
After discovering having POIS, the only 'remedy' that helped me is by far : running, combined with a good diet and normal sleep.(and also avoid bad chemical substances as more as i can)
You don't need a NIKE pair of shoes to exercise.You can find some cheaper ones to begin with from your local market, and when you have the economic comfort you go and buy some good pair of shoes.But for beginning, as i mentioned, you can buy some cheap sport shoes if you like, and if you see that you want to continue exercising, you can start saving some money and buy some good sport shoes.
By the way, i don't think there is something with our hearts. I do sports since a small kid and the past couple of years i do dinstance running (like running 5km or 10). I also had my heart checked by a cardiologist and told me that my heart works perfect.
Hope i helped you Sameer, take care.
