You know what mate? I was like you before. I just ended up quitting regretting because no one will ever know when and how much the price would go up/down. I learned to just play along. Sell whenever there is a slight rise and buy whenever there is a slight drop. Do not wait for a big one because it is not gonna happen.
Same thing with me, I tried to invest my coins before and sell it maybe 3 months ago and now that the bitcoin is increasing it is full of regret in my part knowing that the bitcoin still increasing so fast now.
but I just wonder how can we know that the value of it will increase high or decreases so low, It maybe just got to the point of afraidness that you might lose your money if the bitcoin goes low but then it was all wrong because it is so high now.
i think its now the time to decrease because the price of bitcoin is getting down in under $900 and i think if you buy, you can watch what happen in the market and if you feel you can enter to the order buy, then you can choose the price in more deep but not to deep to choose.