If you plan to hold for a few years as you said this may be a good time to buy some BTC.
However never go all in and do yourself a favour and really only invest money you absolutely don't need!!!
After your initial investment you can do dollar cost averaging. Just buy once a month for 50 bucks for instance and do this over several months or years.
And stay strong in times when price is not mooning!!
So don't panic sell! And store your coins by using a Trezor or a Ledger Nano S!
Good luck and hodl hard!