I agree, trade only makes my BTC decrease.
Trading is good and profitable but it not for everyone, the reason you are probably having a decreased bitcoin is because you are losing your trade, and at the same time, I don’t see any reason why you should even lose your coin, if you only buy and wait till it increase to sell, even when your trade is not going well for you, provided you dint panic sell, you will definitely get your money back when bitcoin increases.
If you really want trade to increase your coin, you need to simply first learn all the necessary skills needed for it, because without skills and strategies, you will only end up always losing to your opponents or do I say to the market. I started trading with 1 BTC and I can confidently tell you that I have increased my portfolio to at least 1.5 BTC.