It is great that you found out about it and enjoyed the money already. Otherwise it could have been a very different (and sad) story.
Hackers are very smart nowadays and if I got this right by the time that was happening you didn't have 2FA which is an invitation for hackers. You were worried about your coins but you didn't activate your 2FA... I guess people never gonna stop being careless.
As I stated above, I had already used a strong password (as I do in every site that requires a login). But after this instance, I didn't only activate 2FA on freebitco.in but on every other platform I have money on (Paypal, CoinBase, Crypto and a couple others). Guess you can never be TOO careful online...!