This is an investor's dilemma, I have a fair share of that dilemma, go up after you sold low, go down after you bought, the volatility of the market always plays a trick on investor's motivation, but as long as you are investing in a good coin like Btcoin, that always bounce back you can always recover what you've lost.
It's really disappointing but when you get the hang of it, you can always try to recover and the good news is you always can as long as you are not giving up.
In order to avoid these things, you could always keep your bitcoin and never sell it. I know that when you have bitcoin and never sell it, it could be 1 million dollars per bitcoin or 1 dollars per bitcoin and it is the same for you because you are not spending it, you are not selling it, it is just there for showing and not used at all so it may not make sense to many people.
However you can get rid of that notion by stating that you are keeping it for your retirement, or for 20+ years and eventually will sell. In 20 years I will not be retired but if I keep my bitcoins and not sell them, I could very well just have a good profit from it and retire earlier than expected for example when I am still relatively young. This is not going to be the case for many people who day trade, but works very well for me so far.