I just crashed my parents car into a land rover.. help?

I had to bring my sister to the station in my parents car, and the car was going alright, stalling once or twice, but on the way back I think the filters were getting congested because I kept on stalling constantly, and I really thought there is no way i'm going to be able to get home, I couldn't go up further than second gear, and I was having to really build up speed to get up any steep gradients. And on a hill just after a corner before my house I met a land rover and went into the front side of it, busting his lights and leaving a fair dent and breaking my front fan, so we both got out he was as expected angry and I was very sorry, and we swapped details, and I just kept apologising, in the end he said well these things happen. Anyway I'm trying to work out if they would have gotten whiplash or anything, because I have it slightly, they were coming down a hill and I was going up. I just keep getting irrational fears that i'm going to be sued by them for whiplash or something..?