Loving son symptoms and conditions

I have a three year old son who has severe allergies. He's been taking singulair for 2 years on & off just in the allergy season. He started taking, singulair again in the beginning of April. One morning he woke up and both eyes were really swollen and red, I called his doctor's office and told them i thought he had pink eye, after 2 different drops and no change I brought him into the doctor's to see if it could be his allergies, and they agreed and started him on Zyrtec. I still was not impressed with the results so i brought him back yet again to see if we could see a specialist. Instead they put him on nasonex to try.
In the beginning of March I started to see a change in my usual happy fun loving son. He was scared to sleep in his bed, waking up in the middle of the night from bad dreams, uncontrollable screaming fits that would last up to an hour, saying he wants a Boo Boo. At first we thought it could be jealously over his new brother, or maybe something at his school.
Then i found this website and everything clicked, how scary it must be for a child to have these horrible thoughts and not be able to understand or stop them. What are the people at merck thinking??
Can any one tell me when the symptoms stop. He's been off for a week and we see some improvements. But he still has these fits with almost an OCD tendency to them (mainly when he's overtired), stomach pains, lack of appetite.