Sorry this is happening to your son. My 10 year old has grand mals (tonic clonic) too. He started with petit mal (absence) and was officially diagnosed in September. In November he had his first grand mal but it was very short and mild so I didn't call 911. We think he had a couple smaller ones in his sleep too since he wet the bed. In December he had a massive one while we were out of state visiting a friend. It lasted a lot longer than the other and the tonic phase (the stiff part) was really scary. He turned blue and all. That is normal for a tonic clonic as the blood is pulled away from the skin to go to the brain as a protection mechanism. After the jerking (clonic phase) he passed out completly and only responded to pain. It really lasted a long time so we called 911. Travis is right, ambulances are expensive. The bill just for that was over $900.
I don't mean to seem callous but you will in some ways get used to them. Your older boy will too. They still scare me but I have to remain calm. If they last less than five minutes and he doesn't hit his head or anything the doctors generally say you don't need a trip to the ER. I now know how they affect my son and how he is after. Sometimes I think the passing out(post-ictal) part is now the scariest since he takes a long time to revive.
I'm also finding out that neuros will often just try to get you to take your child to the ER just because they are too busy to see them. This happened to us this past Monday. My son had two grand mals (one in the morning Sun and one in the evening) he fell out of bed on the second one. I called the neuro to see if he wanted to up meds. My son was really out of it (normal for him after one big seizure, let alone two) and the doc wanted him to go to the ER. He was afraid he may have hit his head and had a concussion. I fought that as the last trip cost $1200 as it was Jan. and we have a $2500 deductible. All due to a bad reaction to too much meds. He agreed to see him in the clinic this time. He was of course fine. When you are the mother of an active boy you know what a concussion looks like.
I just think the neuro had to make a special trip to that clinic and he didn't want to. He was really flip when I told him we have a deductible. He said we just need to get it out of the way. Doctors making 100s of thousands of dollars a year are certainly out of touch. More than the money though I didn't want to spend 7-10 hours in the ER. I loath the ER.
Anyway I will be keeping you in my thoughts and prayers. I know this is so very much to handle. Keep in touch. This is a great place for support. You are not alone in this. It may not get better at first but it may get easier to deal with. The initial shocked feelings lessen after time.