Focussing symptoms and conditions

(A divorced father)
My son has been on Singulair now 5 years and I am in the middle of fighting to get him off. My son is now 7 years old and has been diagnosed with allergies (no test have been done which I find very odd), which leads to a case of mild asthma. This past weekend his mother forgot his Singular on Friday so I could not give him any till the next day, where we met at his soccer game. Saturday night I gave him his usual pill and thankfully due to his exhaustion from playing out side all day he went to sleep in 10 min. vs 3 hrs later which is the norm since Singulair seems to jack him up.
He also has red puffiness under his eyes - most likely allergies.
Seems depressed - just driving down the road and I look at him in the rear view mirror and he just sits and stares into space. When I ask what's wrong he either says nothing or I am tired.
He will try to tell a story or think for himself and just stops mid sentence and says " never mind I am just confused"
He will be having fun one moment and just starts crying or gets depressed.
He was throwing a ball in the house (yes I know) and accidentally knocked a glass over breaking it - he went running to his room, crawled under his bed and sobbed profusely for over 30 min.
He has a hard time doing / focusing on homework - becomes bored very easily.
Does not want to go outside. I will take him to allot of cultural events/ hands on or participation events - he will not try anything. He is unsure and will not come out of his box so to speak.
I spoke with his doctor who was reluctant to take him off, but then agreed that if it was OK with the ex, to take him off for a week to see what happens.
The fun part: My ex is convinced that since he has been on Singulair for 5 years he is fine and does not need to come off it.

1.) Son is diagnosed with mild asthma or allergy induced asthma.
He has never had an allergy test done and has not had a lung function test in over a year.

2.) It is documented that our son has four outbreaks a year. (sounds like the changing of the seasons) but is given Singulair all year round and the dosage has also been increased.

3.) Since the court order, ordered my ex to enroll our son in sports (she would not let him play anything) he does not wheeze or cough uncontrollably.

4.) Since I had to battle to get our son on my insurance I have cut her control issues off a little, but she is refusing to take him off Singular just for a week to see how he reacts. Although I do agree that he should have some form of allergies medicine.

5.) When I found out about the side effects of Singulair, I also found that his doctor was getting ready to add two other allergy medicines to his portfolio - totaling 3 different meds.

I see our sons behavior getting worse and I watch him turn into something he is not and with a controlling individual not believing anything about the side effects it looks like I will have to rely on the medical system to prove my point. I do believe he needs to be accurately tested for allergies and given a regularly lung function test but most of all since he is now on my insurance, a second opinion and a 3rd to narrow down what the situation is and an alternative medical procedure that is fit for the symptoms.