Negative thoughts will make you weak, the result is like that what you said, you will quit or stop but the positive will make even you had lose already a money, the result you will be a successful person.
So put into your mind the positive thought thoughts with wise personality and actions.
I like what you said, and its the fact that losing or frustrations are part of growing. Since we are into bitcoin / trading industry, losing is essential and if you can't accept the fact of losing then this is not for you. But if you will not give up and you manage to stand again then for sure success is going to be with you, just don't give up.
Its really easy to say to someone on not to give up easily but if you are on his situation you would surely feel the same way too and in OP's situation its not an easy thing 7 btc loss is already a big amount and hes been trading already for 2 years which is long enough and he seems his trading skills doesnt work at all thats why he decide to quit to stop further more loss.