We are on a bear market. Next year will have bull market.
If you believe on cryptocurrencies, the time to buy them is when they are with low value.
Bitcoin is increasing on value, but can't be compared on how it grew on 2017 November/December.
About buying Bitcoin and cryptocurrencies, I suggest you the CoinBundle platform. They haves no fees when buying, is instant (no need to buy/sell order waiting), easier and you can withdraw directly to your bank. Also, you can buy crypto using your credit card.
What is a plus on CoinBundle being different is that instead of buying individual coins (and hardly choosing which coins to add to your portfolio) you buy an already done portfolio (bundle) that contains the coins you trust.
Try it and share your thoughts. There are many bundles available. Personally I think the best for you is the conservative, but do your own research