Do you weigh too much, or too little? I can solve that for you. Count how many calories you take in, then count how many calories you burn through activity. If you want to lose weight, make sure that your calories-in are less than your calories-out. If you want to gain weight, reverse the process. There is no other way to reliably regulate your weight.
A top-tip: if you want to reduce calories-in, an easy first step is to not drink any calories. That means no drinking soda or alcohol. Period. That's also an easy way to save a lot of money.