About to have sex for the first time in a year and I'm scared shitless

I'm going to visit my ex-girlfriend. We haven't had sex in a year, only one small encounter where we fooled around. I have been trying to get my shit in order and just decided to stop dating for a while. But, tonight, it's time.

I'm worried when I have sex I won't be able to cum since I've been masturbating for a year. I last did this morning and am having a hard time not doing it again (I'm a two-a-day guy.) Any advice? Any tips?

Edit: Just wanted to add it's not like -right- now, but in about 3 or 4 hours. I'm trying to stay calm and just listen to some music.

Update: Ze sex did not happen. Thanks for the advice though, it really gave me some confidence. Most appreciated.