Don't worry too much.. You baby well be ok!!
I had my first at 28 weeks and baby was only 1lb 9oz. She spent 3 months in NICU and had some health issues after, but now she is a healthy 15 months old!
I've seen lots of 7 months preemies. They have very high survival rates and most dont have any long term problems.
I know its still difficult but try to stay calm. You need to be strong. The baby will prob spend 1-2 months in NICU, so you have to be prepared for that. Good thing is the staff and doctors are usually very knowledable and really care a lot for the babies they treat. They also encourage you to come to NICU as often as possible, and you have access to your baby 24/7.
Things happen and every delivery is different. Just be greatful that you've made it this far and are our of the woods pretty much. Your baby will just need extra care for the first several months of his life but afterwards I'm sure you won't be able to tell the difference from full term babies!
Good luck and God bless!!