My Proposed PhD supervisor is ignoring my email
This is obviously an important decision for you, and it's understandably making you anxious. However, you have to accept that the decision won't be made until March. Repeatedly contacting the folks making the decision, asking if they've decided won't help. They have a process they have to follow, and they can't make promises before they've completed that process. Sending repeated emails asking about the status of their decision could be annoying them (it would annoy me), but if they're reasonable, professional people it probably won't affect their decision on the position. However, no one can guarantee that. You just have to live with the uncertainty for a couple of months.

As long as your application is complete and accurate you should just put this aside until March. Find something else to keep yourself busy, or seek professional assistance if the anxiety is overwhelming.