HI A.! My son was also diagnosed w/ ADHD recently. We have decided not to medicate at this time because he is so "hit and miss" w his attention span. He has tantrums daily! As a matter of fact, he had one today! lol What we have done instead is taken him to Children's Therapy Center in Peters Twp. They are working w/ his school in Mt. Lebanon to encourage a "sensory diet" to improve his learning skills and lesson his tantrums. We started very late in his Kindergarten year, so hopefully, it will be more effective in 1st grade.
What I have found with our school district is immediately get him an IEP for next year so he can catch up with his class socially. Our biggest challenge right now is to get him socially acclimated (sp) although he is not up to par academically. From what I've heard, eventually they'll learn their own way of picking up on when they need a break from the group; & learn their own way of learning to read, socialize etc. They take my son to a learning support room to calm him from his tantrum.
In our case there has been a lot more issues that have come up like dypraxia, sensory issues, etc. and we are very new to all of this. What we have learned also is ADHD has a broad variety of issues but as parents we need to have patience (which is difficult for me) and acceptance that they are bound to have meltdowns because of their "disability" but also some of that is being 6 or 7 or whatever comes with that of their typical age group.
Just about me: I try to be the best parent I can be to my two kids. I am not perfect, by any means, but no one is. And having a child w/ any disability is a challenge. Whether it's diagnosed or not lol!!! I have a 4 yr old who is typical for her age, but she still gets on my nerves because she acts like she's 9! We're all human as were our parents who we loathe beacause of "stupid" things they said like "when I was your age..."
Keep your head up, A.. And look for many resources. It sounds like your son might benefit with a sensory diet. It consists of a variety of things from weighted blankets to swinging to get that energy out. I know it may seem the more we try to desensitize them they more wound up they get but it may work. I'm in the same boat right now, wondering if I'm doing the right thing. But it's worth a shot!!
Good luck.