When you do a trade that goes wrong, you now have 4 things to deal with. If you deal with them, you are on your way to becoming a good trader.
I call them the 4 R's
1. R E A C T . I have a bad trade, what can I do?
2. R E S P O N D . How quickly you implement that plan before the position gets worse.
3. R E V I V E . Take a short break and compose yourself. 2 minutes is fine.
4. R E C O V E R . Get back in the zone, trade well and SLOWLY recover the error.
If you do all that well, the loss will not be very bad and should be recovered in the next trade or two.
A lot of small wins will not compensate for a large loss and after a large loss you will have a lot less capital to recover it with.
Remember, trading is not about winning money, it is about eliminating losses. The rest takes care of itself.