You should have got grace period. You should have applied for the school when you know that you are not getting sponsored or only choice was go back to school. Don't let it go for more than 6 months or you'll be barred from entering US for 10 years. I think 3 months of out of status is 3 years bar. I think you still got some time so hurry the F up and get in status before its too late. Talk to new/old international adviser or the lawyer if you intend to stay in US with valid status.