Shaving butt-inflamed hair follicles?

So I shaved my butt twice, using hair removal cream.
1st time was ok, removed hair, exofilated my butt. I was smooth etc.
2nd time was week later. I did it the same way. It was okay for 3 days, but today I went to work and after I came back, my buttcheeks have this rash of inflamed hair follicles? WTH!?
(Only buttcheeks, there is no problem near butthole).

I did it the same way as 1st time, so what exactly happened? Any tips? It's freaking painfull and itchy now.
Thanks for advice