No one would waste LSD by putting it on shrooms - it's just not worth the cost. Plus you could if you trip lasted 4 hours or so it was mushrooms, if it lasted about 12, then it was acid. But I don't think you have to worry about that. You just had a bad trip bro. Sorry to say it, but driving arround in a car and going to McDonnalds are not the best sets and settings. Next time (if you decide to do it again) do em while chillin with a few close friends at a house with plenty of entertaining things to do - go for a walk (my favorite) watch a trippy movie just keep yourself occupied and if you start having bad thoughts force yourself to think about something else.
No doubt man..setting is everything when you're on mushrooms. I like to be out in the woods so I can go for walks. You have to be able to change your setting when you feel a bad vibe coming on. Reality is something that you just can't deal with. I know what you mean by feeling so scared and alone. I've gotten like that a couple of times. That's why you have to have responsible friends there to give you plenty of reassurance and hugs when you need it. Bad vibes will ruin your trip every time. You just have to know how to channel them. It's just dangerous riding around and going to public places like McDonalds. It's a wonder someone wasn't killed. I know for a fact I'd positively die if I had to drive on shrooms. I wish you would have had a better experience your first time. Don't let it discourage you..just change your setting next time.
Just think positive, and remember that you're on drugs and they change your perceptions. That's all there is to it. And of course, setting does have something to do with it. Whenever I'm tripping, I tend to stay away from public places with lots of people (except for the time I tripped through a lecture class sophmore year of college. That was fun.) But I find I get the best results when I eat mushrooms with several friends. Also, try tripping during the day, as well as at night, they make for very different experiences. Most of the time, whenever I do shrooms, I eat them as soon as I wake up. That makes for the best trip IMO.