2km in 12 minutes, possible as a new runner?

Hello! I'm a returning runner after a knee injury a year ago, started running literally last week lol. Anyways, I'm doing this because that mark is my country's army endurance test and I'm currently at 6 minutes per km. Yeah I know that pace will make me pass the test but the thing is, my calves (back and front) start to burn reeeeeally hard after just 200m into the run, I also get a sharp kind of pain in my inner right ankle.

I wanna drop that pace to 5-5:30 minutes and I have only one month left, the only thing keeping me from doing it is that burning feeling and the pain which is just try to push through.

Don't know what's causing it, and I'm wondering if i should just drop the running and be careful because of that or just keep doing it.

Any advice? Thanks in advance!