I am so sorry that you are having to deal with this excruciating condition at your young age. I am 55 and was diagnosed with trigeminal neuralgia about a month ago. I have dealt with a lot of pain since I was 4 yrs. old, but this was something else as you know. I couldn't eat anything solid for almost 4 weeks. Then to top it off I had a bone fragment break off and poke out through my gums and was slicing the side of my tongue. I guess when it rains it pours.
I am sorry to be the bearer of bad news, but I believe that this is a condition that will stay with you from now on. The good news is that it may be a long while before you have another attack. When you do, take your pain meds on a regular schedule until it clears up completely. Pain meds usually tend to have to build up in you system to work properly, so just taking them now and then really doesn't do much good. Eat things that are soft ( and boring), like jello, toast dunked in your favorite warm beverage, well cooked pasta, you get the idea. I also found that appling one of those frozen gel packs to the are really helped a lot. Stay quiet, don't talk too much and don't hang around with anyone funny, because it hurts to smile.
Standing in the rain didn't cause your pain. That nerve gets irritated and bingo, pain. Maybe you were clenching or grinding your teeth, maybe you ate something that was hard to chew. I find mine acts up when I am stressed out and tensing up my muscles.
Hope it helps to know that you are not alone. Keep a good thought and if you ever want someone to talk to who knows what you are going thru, I'm usually here every couple of days at least.