Don't lose hope in every mistakes it is the journey to forward in the success. Many people succeed in their life it is because of mistakes after that they work hard. They make a decision not to give up and try and try.
Yes, when we are having faith within our knowledge and strategies then we do not get disappointments on seeing any losses because we will be having confident to recover the losses and then multiply the capitals. Mistakes may happen at any time because even professional traders also may slip down sometimes as market fluctuations are not predictable all the times.
to me i think i personally never disappointed in trading. i am doing trad for a long time some time i earn money while some time i also face lost but i never disappointed in gambling. whenever i start using continuously, then i try to change my trading method. which at least prevent me from further lost and when i realize that now i can get my confidence back then i start trading in normal form, but i never get disappointed in trading while losing money.
I think all people lost in trading but its not mean you stop . Try to learn from the mistake you did. Try and try until you succeed. Right if you failed in trading try to change your trading method or strategy . Just also do it a research before buying altcoin to make that altcoin you want to buy have potential or not. Dont be afraid if you lost in trading just continue to trade and you will see happen and you will earn money. You need also a patience and dont pull all your bitcoin in one altcoin.