As a consequence, I get one of the worst trades of the period, my target was 50% Up and I closed the position with only 5% profit...

There are two ways to look at it.

1. You have still made a profit no matter how small it is.
2. You may have made a larger profit investing in something else.
   I'd say don't torture yourself, you haven't lost anything. Maybe your next investment will be better :)