Rather than to say you got some $$$ for free, take this money as an evidence that he left for you and I hope you have at least that text message that states about him offering you money.
Probably if you never replied for his msgs you wouldn't be in any state of concern. The best thing you can do is that you shouldn't spend that money and you should start doing something immediately about it.
It took 2 damn years to do this? Your actions seems to be like "Fun Time Revenge".
The worst thing you can do about this is posting it on public forums. I hope you haven't posted this on Facebook or Twitter