I already have disordered sleep and eating habits, as well as pretty bad anxiety.

So the neurochemical side of anxiety is a bit tricky to pin down because often, especially for ADHDers, it's a lack of norepinephrine (adrenaline) that causes it however you may be very sensitive to it or you may have an excess of it which is causing anxiety instead. Because of course it's not just a simple matter of it being an excess - that would be too simple.

There's really only one way to find out and that's via tinkering with your norepinephrine levels. Sorry that I don't have a clearcut answer for you.

If you've ever taken a medication that is an SNRI or that has similar norepinephrinergic effects, e.g. venlafaxine, you'll be able to get a decent understanding of which side of the norepinephrine equation you find yourself on.

It's hard to know exactly what would be the right path forward in a general sense because it's important to understand the causes in order to address them. For example, one person might have disordered eating due to being extremely anxious all of the time and then the fix is "simply" to treat the anxiety and voilà. On the other hand if the disordered eating is rooted in something like body dysmorphia then doing something to increase appetite such as trying mirtazapine may help appetite but it might aggravate the underlying psychological issues and make things worse.

As very general advice, for ADHDers who experience anxiety and insomnia I think one of the best options is trying clonidine. This doesn't work for every ADHDer but it helps with impulsivity, anxiety and the trauma response, rejection sensitive dysphoria, and insomnia.

I have also had really good success with amantadine for treating anxiety, plus it's a dopamine reuptake inhibitor which is an added bonus for ADHDers although its usage for mental health and ADHD is still very very much in its infancy and I've been trailblazing its use where I live and you'd probably need a prescribing doctor who is comfortable with prescribing off the beaten path. Amantadine has a very low side effect profile and it seems to be very well tolerated.

I feel like non-stimulant meds would be the right choice for me for a number of reasons.

Fair enough. Don't go over sharing beyond what you're comfortable with but if the concern is addiction issues then keep in mind that appropriately medicated ADHDers have a way lower risk of addiction because that need for dopamine is already addressed by prescription meds and so the urge to engage in behaviours that provide that kick are usually dramatically reduced and much more manageable. There are some meds like Vyvanse that are pretty difficult to abuse as well. Stimulant meds will reduce your appetite so this can be a problem for people who are prone to disordered eating like anorexia. It's a bit of a crapshoot to figure out if stimulant meds will increase or reduce anxiety too.

As for alternatives, I think that guanfacine is a pretty safe bet - the side effects aren't wild and it can help with anxiety, although I think that clonidine works better in this regard. Dosage for adults is a bit tricky but I've heard reports of very high doses working for some people - in the vicinity of 6-8mg. Guanfacine usually works best as an adjunct medication.

There's a lot of norepinephrine reuptake inhibitors that may help but I won't go into depth on them. There are a few dopamine reuptake inhibitors, such as atomoxetine, but as these are mostly antidepressants they tend to come with significant side effects (atomoxetine especially) and it takes a while to taper up to the right dose. That being said, for some people a medication like atomoxetine is a complete game changer. Atomoxetine also increases dopamine in specific areas of the brain, which is unique to it, and thus it lacks the broad-spectrum effect that a classic stimulant has so it can work really well for some people but for others who have a more global dopamine issue it may have a limited effect or no notable positive effect.

One medication that I think is grossly underrated by psychiatrists for ADHD is modafinil. While this is technically still a stimulant, it's not the same as the classic stimulants and it does not have any significant norepinephrinergic effect nor does it have significant addiction potential. The lack of norepinephrinergic effect can make it less useful for certain people but, where classic stimulants are not tolerated, it can be a good option. Just keep in mind that it's drug that has sulfonamide and thus if you have any allergic reactions to meds this may not be suitable for you and you want to know the symptoms of Steven-Johnson Syndrome just to be aware of it if they start to manifest while taking modafinil. It's not a huge thing to worry about but there's a small chance of it happening so it's always worth mentioning when talking about modafinil.

I can speak to personal experience with a lot of this stuff but tbh my experiences are a bit more uncommon and it's probably better going into this stuff with the understanding of how these meds generally tend to work than it is understanding my less-usual response. I hope this is helpful!

I have taken Straterra(atomoxetine) before. It made me feel "normal". I had to stop taking it because of some gnarly physical side effects, and that annoyed me because I felt I was able to integrate into society better while on it.