How to improve my 10km time (running)

Hey everyone,

I love to run and have a 10km race lined up for the 1st of May.
My boyfriend, his sister, his dad and I did this run 5 years ago (I was about 10kgs heavier then and a SAD eater).
My boyfriend's dad unfortunately passed away due to a heart attack last month (smoking, alcohol, unhealthy food --> unhealthy heart) and his mum asked us whether we would still like to do the run.
So we're doing it in Steve's memory.

So far so good. I am training 3x a week at the moment. I usually run about 5k (easy - 30min) on Tuesdays, then about 7km on Thursdays and do a 10km (as best I can) on Sunday mornings. The rest of the week I walk to work and home 3-4 days a week (1hour each way), but that's about all I have time for due to full-time study, part-time work and it being graduate recruitment time at the moment.

I'm okay with my training but I want to make sure I get a good time in my race. 5 years back I did it in about 58min. or so.
At the moment (today) my run takes me 55:18. I feel great - improved by over 1 min. from last week.

My boyfriend is quite competitive and will probably run around 50min or less. He did 46 last time, but he put on weight (muscles) since then and is about 5-7kgs heavier. He has flat feet, but long legs and is lean.

So, do I have any chances of getting close to 50min. or even beating him by 1st May?
I'm not really that competitive, it's more a "Monkey Diet" vs. Meat and Protein-Shakes.
He fully accepts my way of eating and we're fine with our completely opposite diets, but I would earn much more respect, I think, if I kicked his nice arse :-).

Any good tips?

Also, would banana island in the week before the race be beneficial (have never done it so far) or should I just stick to my routine?

Thanks for all your help
Fruity raw love,

Eva (811rv since 8 March - never felt better!!!)