Is it okay that I slept with my now step cousin
It's not really okay. How did sex with your now step cousin make you feel?
There is no such thing as "good" and "bad" regarding sex.
Well, I guess from your answer the sex was enjoyable. Even though you guys are not blood-related it's a bit taboo now considering you slept with a cousin. You might start getting a lot of crap from people who love to voice their opinions, so I hope the sex was worth it.
I didn't get crap from anyone and people agreed that love have no boundaries.
Considering that you call them your step cousin, I'm assuming that you were raised as cousins. If so you should really avoid letting this happen again. Sleeping with cousins is generally frowned upon, and can lead to issues within your family.