Hey, at least it's not the endoftheworld. Don't be to hard on yourself. Rumor has it guys have a hard time getting hard if they haven't had sex in a long time, so the added stress makes it a mission impossible.

Don't focus on penetrating her. Focus on getting hard. Blowjobs are a great way for you to get aroused. What's easier, have her get on top of you so that she's putting your sex inside her. Try out different positions. As long as you're hard and she is physically ready, her body will accept you whether you're putting it in or she's climbing on top.