You should have bought btc while it was cheaper i know its easier said than done but that's a fact when everyone is expecting good returns because of the btc halving. If you really want to earn good return then you should take the risk. Not all the time btc's price is dropping there are certain time it will pump.
Well it was already in the past, there is nothing OP can do about it right now. All he can do is look for another opportunity to buy Bitcoin at lower price and I think today might be a good time. There are still several months before the halving and Bitcoin rally is just starting and it is best to buy during the start of a rally then sell on or after the peak right before the price goes down. That way he will get a good profit from his investment.