First of all congratulations are in order That's fabulous.

Second, get in touch with your campus and talk to them about disability accomodations. It will make your life so much easier if you can do this for yourself.

Third, is there anywhere you can practice? Maybe with a friend or a relative along in case you need help? The best way to lessen anxiety about highway driving is to do it often and as part of a routine, so maybe you could set aside some regular time per week to go on a short drive with someone you trust.