First of, congratulations on massive increase on your investment! Yay!

Secondly, I'm not an expert but I think to sell or not to sell depends on what your goal is.

One thing you might want to ask yourself is- what is a gain that I'm comfortable with for this investment?

The answer to this question varies per person, hence some would sell at 20% gain, others would wait for a 10x return.

Some say BTC will go back down to $7k mark. Others say it is on its way to $30k. If you do sell, and in case the price shoots up, don't focus on the opportunity lost, but rather focus on the gains enjoyed.

If you don't sell and the price goes down to $7k, hey you're still at a profit!

Good luck! :)