It helps to know why you are in flight school as well. Way back when...I was just starting API, I received a "Dear John" letter from my fiance in Dallas, Texas.
Believe me I was an emotional wreck. But I had vivid memories of my 1st Class cruise on the William C. Law. Every day we were at sea on that "tin can" (destroyer), I was sea sick. It helped reinforce my decision to go aviation.
Although it is pretty much universally advised to stay single during flight school, take it with a grain of salt. It reminds me of back in high school when everyone preached abstinence as the only logical method of birth control. Let's be realistic: People are going to screw, and people are going to enter into relationships with women (in the case of an SNA, probably a mindblowingly attractive woman that happens to be very good in bed).
I think it's all about compartmentalization. You have to be good at it. You have to keep other areas of your life separated or divided in a manner that prevents them from negatively impacting eachother should problems arise. If you are the type of person that can't help but bring the baggage of your home/social life to work with you, you are playing with fire by dating in flight school.
I just got out of a 3 year uber-serious relaitonship (started before OCS and I'm just finishing up strike training). Although it was very taxing, I was able to leave it at home and focus and study on my flights. I think that flight training naturally builds that skill into folks. Although I've only been in naval aviation for a couple years, it has really taught me to isolate from the distractions and focus on the task at hand. I'd probably say looking down at the boat during CQ for the first time was one of those 'pucker factor' moments that taxed my ability to compartmentalize and focus the most. The biggest thing you can do for yourself is to get the hell out if the relationship is draining more from you than it is contributing (if it's toxic).
One time while we were unloading the COD on deck, a yellow shirt came into the plane bitching about something or other. I was preoccupied (pissed off) trying to get a Tomcat engine out of the plane and get the plane reloaded for the next launch in about 20 minutes. Long story short, I told him to get the phuck out of my plane we had work to do. It turned out he was the Flight Deck Officer. That didn't work out for me so well.