You must treat stock investing as a business and plan every move. Buying and selling stocks and shares is not a hobby if you do not research, plan and understand every purchase, you are just gambling. Do not buy when you are bored. Limit your holding to no more than 20 stocks, this is the maximum number you can monitor. Even 20 May be far too many for some. Use stop losses to protect your holdings from incurring too large possible losses if the stock price drops. Also set up a limit order this will automatically sell your holding of a stock when the stock price reaches the price you would like to sell at.
If you haven’t applied these rules, do not invest any more money until you have thoroughly reviewed and taken all necessary action on your existing portfolio. Only then move forward in your new stock investing business.