Flatmate Reports Minor Assault to Police. What Should I Do

My question involves criminal law for the state of: United Kingdom!

my flatmate had been heavily drinking on Sunday evening with friends in the kitchen. By 1:30am I couldn't take the noise any longer so went in to tell them finish up. I probably said it in a mean, aggressive way, but a fight broke out between us. None of us suffered serious injury. Just the odd bruise. 4 days later the police knock on the door and arrest me. I'm assuming he reported it to the police much later. The solicitor assigned to my case tells me I probably shouldn't report/press charges on my side as it could work against me. Because my flatmate reported it first and he had friends who will testify against me, things aren't looking good.

Any suggestion what I should do, NOW?

The UK isn't a state, this forum is US law only.

Were those friends present at the time of the fight? I don't know anything about the legal system over there but i doubt they would allow testimony from people who weren't even there.