But, I think it's okay to sell sometimes. Taking partial profits can help if you need money for living expenses.
Of course guys may have pointed some things out to you above but yet I will still have to add a little bit.
Firstly before you investment in bitcoin you must have made some kind of self examination to know how much of your discretionary income could go into bitcoin investment hence it's only advise to invest in bitcoin what you can afford to do without in a long period but when you talk of selling it means you're certainly new and from your profile I will end by saying you have a lot of reading to do here and around the forum to know what you are saying.
They is a reason why they say you should invest what you can afford to do without in a very long term (discretionary income).
Just do some reading.