SOL and the 7.5 year report period are different.
SOL depends upon the state where you live and that determines whether a creditor can sue you. Reporting period is how long adverse info can be reported to the CRAs.
If all you have are these collections, let 'em lie. They ain't gonna go anywhere. Are they calling, writing and threatening?
When do you start back school and when is tuition due?
Assuming you had the cash to PIF all your collections today, it's going to take a month or more for that to update on your CRs. Even then, paying collections ain't gonna help your FICOs. A PFD will likely take several weeks to negotiate.
With a 630, you could probably get a credit card, but I suspect it'll have a low limit--probably under $1,000. I'm not trying to discourage you from applying, but if you're thinking you could get a $10K limit I'm probably bursting that bubble.
Do you have an account with a bank or CU? A student loan or a signature loan from a bank or CU might be your best bet.