Just don't worry about bitcoin investment You're welcome to invest. Don't listen to that people who are telling you the the 2017's December history. They're the people who become panic and sell there coins. Bitcoin is unstoppable and investing in 2019 is still worth it.
Yes this is best time to invest in bitcoin because price is not very high and we can reliably increase our money, I am sure 2019 will be best year because now a day we can notice in market price has started to become high, in 2018 it was low so we bought and still it is opportunity but price has already started to go high so dont wait anymore future is bright.