lost the spark

My boyfriend and I have been dating for almost three years, and our relationship feels like it's coming to the end. We argue constantly, especially about the way each of us is acting. I've tried everything I can to change myself and my behavior to be a better partner and best friend, but it doesn't seem like it's enough anymore. I even have tried planning more dates to bring the romantic spark back, but they never seem to work out. For example, last night I planned a romantic movie under the stars. It was going really well, but then our hammock ripped. We decided to move inside, only to have my laptop's dvd player stop working. After picking a movie on Netflix, he realized he had to go back to his apartment to get insulin (he's a diabetic). At this point, it was already 11 and we both work in the morning, so he decided it wasn't worth it to come back over after he went home. Every date seems to go like this; things happen out of our control that make it difficult for us to enjoy our time together. I'm not sure how to bring the spark back in our relationship in order to make it feel less boring. Any advice would be appreciated!