Probably not sugar-coating, but still positive. You're getting answers now, and with a diagnosis, you can treat. Here's kinda the sorta thing we said to DD - maybe this will spur some thoughts as to what would be appropriate for your son:
From all that assessment you did, we've got some great information about how your brain works, and how you need to work and be taught in order to learn, and to show what you know. You know how you find X really hard/ frustrating to do? Well, there's a good reason for that. Your brain is wired differently, and it doesn't get there the same way everyone else does. You can do X, it's just that to get there, we need to take a different route....
Over the next couple of days, you can start to talk about what that route might look like, and some of the pieces that might come in in the short and long term. Just knowing there's a real, concrete, biological reason why X is so hard for him and so easy for others can be a huge relief. Knowing that he can start reducing his hand-writing load and finding alternate forms and ways to create output might give him a really positive starting view on his diagnosis and accommodations. Just think how much fun it will be writing an IEP that says he doesn't need to (insert dramatic horror movie music here) "show his work" once he's demonstrated understanding of a math concept!
You also want to be honest - but calm, constructive, and matter of fact - about the negatives (not today, but over the next weeks and months). Don't overstate the problem, but don't duck his questions either. Focus on "we have this knowledge, so here's what we can do about it." There are things that will continue to be hard, where a Plan B is important (for us, that means lots of audiobooks, voice-to-text etc instead of expecting her to read everything herself; for you, that might be typing/ voice-recognition in lieu of hand-writing). Also, remediation might be required. Our reading program is, by definition, "explicit and repetitive", just like the psych report calls for. We've gone back to pre-K reading skills, and are slowly working our way up, not missing a single. microscopic. incremental. step. Gifted Hades. I try to make it as fun as possible, but when she says it's boring and repetitive, I agree, yes it is. But this is what we need to do to connect the part of your brain which you're currently using to read, with the part of your brain that we need to activate for reading.* Yup, it sucks to spend your free time doing this every day. But it works, and we're going to keep on doing it. And every bit of this we do makes your life at school easier. I don't pretend it's fun - but I do have an incredibly positive attitude about it. Short term pain indeed, but the long-term gain is huge.
Oops, more preaching. This is all very current for us, and I can't yet write in any kind of detached manner. MON has great advice above about how to life with these kinds of disabilities in the long-term, something we haven't experienced yet. I just wanted to share some thoughts about getting through the next few weeks, as well as let you know how much good you can also do, even in the short term.
Hope this helps. Sorry for length!
*Note: she LOVES the MRI pictures that show typical and before and after scans of dyslexic brains, demonstrating the new connections/ activations created with OG reading remediation. I swear some days we can both actually see the neurons channelling their new pathways and hooking everything up.
