I know exactly how hard that doctor appointment was for you. It is so heartbreaking, but you have to do it or else there is no help. Given basic fairly consistent parenting, most kids will thrive. When a kid doesn't, there is a problem. One member here some years ago liked the phrase "Kids do well when they CAN." She meant that if your kid isn't doing well, something is wrong and your kid needs help. The earlier you get help, the more good it can do.
Is your son sensitive to light, sound, taste, texture, a picky eater? Wants clothes that are too loose or too tight? One thing that can be a real struggle for kids is sensory integration/processing disorder. This is when their brain isn't handling input from the senses in the way it should. The entire world is "too" or "not enough". My kids all have this to one extent or another and I have it pretty bad. I simply cannot handle some things. Thankfully my mother had her own issues with sensory stuff (unknowingly) and made sure I never had to wear anything itchy (I totally cannot cope with that) and she did not force me to eat more than 3 small bites of new foods. She did make me eat those 3 bites, and that was a battle at times. But overall she understood that I wasn't choosing to be difficult even when I couldn't put the problem into words.
Many (if not most) kids with adhd have sensory issues, according to several doctors I have worked with. I can tell you more about this if you would like.
My oldest has Aspergers (or whatever it is now called) and he had a lot of the symptoms of adhd that you are seeing. Medication was heaven-sent for him. While we didn't use Intuniv ever, he was on various forms of ritalin and adderall. I had SOOOOOOOOOOOOOOO many people tell me that he would grow up to be a junkie if we put him on stimulants. Guess what? He is incredibly anti-illegal-drugs and at almost 28 he still takes his medications daily. Why? They help him be in control of his life. He never runs out in a month, there are zero signs of addiction. I believe that without medication for his adhd and moods, he would have sought out illegal substances to make him feel better. WIth the use of prescriptions, and with listening closely to him to hear when he said a medication was causing a problem, we were able to help him create a MUCH better future. Of COURSE this is super personal and it is a decision that you have to make according to what you feel and believe to be right for your son. I just wanted to let you know that in spite of what some people will say, medication can be extremely helpful.
A couple of things that really helped our family cope were protein and realizing that we just couldn't do everything that others could do. If my son didn't have a fairly high amount of protein each day, the outbursts were horrific. If he had a lot of sugar and no protein? OMG it was even worse! I learned to keep a stock of protein bars at home at ALL times. I never went anywhere without protein bars or enough cash to stop and buy one at a gas station. If we needed to go to the store on the way home from school, my son would be okay at the store almost always. BUT if he didn't have a high protein snack either before we went to the store or while we were in the store, he would just fall apart when we got home. He was just unable to cope and it took the form of a total, incredibly violent meltdown. If I gave him a protein bar or got popcorn chicken or whatever that had a fairly high amt of protein? I had a very different kid unless something awful had happened at school.
It is frustrating, but they fall apart only around those they trust the most. So he will likely NOT fall apart around strangers or those he doesn't trust for some reason. Around Mom? Bring on the awful meltdowns! It really stinks, but it is because they trust us to love them no matter what. Getting a handle on a higer protein, lower bad carb/sugar diet may be of some help. Not everyone here sees it the way I did with my kids, but the change can be super helpful. Of course I have a brother who is still that way. I would rather be around him drunk than after a candy bar on an empty stomach. And he is a mean drunk. My son wasn't nearly that bad, but there was a definite improvement with a higher level of protein at regular intervals.