-masturbating using your hand is the most common technique, but whatever floats your boat.
-it's perfectly normal for your penis to have a curve. Very few men have a perfectly straight penis. The only thing you need to worry about is if you think the curve was caused by an injury/accident.
-masturbating 3 times a day might be a little much. Each time you ejaculate prolactin hormone, phenylethylamine (also found in chocolate) and endorphins are released from your body. It takes several days (48-72 hrs) for your body to recover from releasing these chemicals. Lack of these chemicals may become addictive and abstinence may result in cravings and mild depression. You shouldn't stop masturbating; ejaculating is the best way to help keep your prostate healthy. But you might want to cut back to like once every day or so.
Hope this helps!