If there were ways of doing this without investing, trading, spending time or risk being a victim, i guess everybody would be doing it, right? You're not talking about making 2% profit in 1 year, you're talking about 1000% in 2 months...
In your case, i think you'll have to take a very easy decission:
Either:
1) confess to your parents what you've done
2) take a loan, pay your parents back, get an IRL job to pay back your loan.
I'm also going to advice him the same thing honesty is still the best policy if you are not going to do this,you might end up losing all bitcoin that is left to you number is also good provided that your parents will not know about your loans this is a big lesson for you and for us as well..