Learning Trade Forex

Half size trade.
Holding on to a trade is very hard for me. Whole time I'm guessing should I get out or hold it more. No matter where I exit in the end it usually feels bad because it continues in that direction and I miss out or it bounces before I exit and I don't take what I had moments before. That's why I usually scalp fast market because it doesn't give me this kind of headache.