Hard luck Lorraine,
I think you've a good chance if it's a mile strain... (but it will mess up your training programme a bit!)
As for tips for recovery, sprains should be treated with the normal RICE treatment. You should have started this soon after the injury...
Rest for a couple of days... but don't over-rest it after this - need some movement. Hopefully you did this.
Ice.. put an ice pack on every few hours on the swollen area. Don't forget to put the ice in a towel or something to protect the skin.
Compress... bandage up during the day. Enough to give good support without killing circulation.
Elevate... lifting your leg above heart level will help reduce swelling... so sit back and watch the telly!
Then what?... well hopefully you've done some of the above, and it's feeling a bit better...you should be looking to do some stretching and movement. But really, I'm going to stop now. You must have invested a lot in plane travel, hotels etc for NY... I suggest you go and invest 30-40 quid more, and go and see a good sports physio. Far better than taking tips of the forum!