I still don't think you have ADHD because you can write such long posts and manage to keep attention whilst doing it (?). That seems IMO like something an ADHD sufferer would not be able to do.
ADHD 1, a. Often fails to give close attention to details or makes careless mistakes in
schoolwork, at work, or during other activities (e.g., overlooks or misses details,
work is inaccurate).
b. Often has difficulty sustaining attention in tasks or play activities (e.g., has difficulty remaining focused during lectures, conversations, or lengthy reading).
h. Is often easily distracted by extraneous stimuli (for older adolescents and
adults, may include unrelated thoughts).
Melatonin will ALLOW you to sleep but it will not make you tired, ie. depress your CNS and brain activity. If you want something that WILL make you tired and relaxed try a benzodiazapine. Benzodiazepines would also probably work to relax you and decrease any anxiety symptoms but it probably/might make you tired. They are essentially used as a sedative for people who have trouble sleeping or have acute mania and psychosis. People sometimes get a dependency on the stuff to relax them but it isn't really addictive IMO. http://ocw.mit.edu/ans7870/SP/SP.236/S09/lecturenotes/drugchart.htm
Adderall IS an amphetamine and COULD be causing the anxiety and ADHD like symptoms. It depends, do you feel like you have worsening ADHD/anxiety symptoms or does the Adderall make it better? It is used to treat ADHD but it is still primarily an amphetamine and for people that don't have adhd or it just doesn't suit will be OVER stimulated and can/could get ADHD and anxiety like symptoms (essentially it is speed). If the adderall makes it worse or you notice no improvement I'd suggest to get off it.
It's important to remember there are a lot of different classes/types of antidepressant. Where one type may not work for someone, another type may. These days doctors and psychiatrists have a real fad with prescribing the newer types of AD, primarily SSRIs and SNRI types. Down fall is since they are reuptake inhibitors they CAN trap serotonin or serotonin and noradrenaline (in the case of snri) in the synaptic cleft and essentially increase biological anxiety symptoms and make people feel worse (happened to me).
These are the AD drug types:
SSRIs: Selective serotonin reuptake inhibitors,
SNRIs: Serotonin and noradrenaline reuptake inhibitors,
TCAs: Tricyclic antidepressants,
NASSAs: Noradrenergic and specific serotonin antagonists,
MAOIs: Monoamine oxidase inhibitors (irreversible)
RIMAs: Reversible inhibitors of monoamine oxidase
NARIs: Noradrenaline reuptake inhibitors
NDRIs: Noradrenaline/dopamine reuptake inhibitors
SARIs: Seratonin antagonist reuptake inhibitors
I reccomend you try different AD types, just trial one for a few months and if you don't like it try another one. I hated SSRI and I switched over to TCA and it is much better. TCA is an older type of AD though that can have more side effects (hence why they prescribe newer ADs).
Ok I see you're already on 2 benzodiazepines. It is possible that the adderall is causing in part the paranoia and anxiety. Honesty you are on so much already I'd almost be tempted to suggest you get OFF every single thing (yes including the alcohol and weed) and wait a few months then start on a AD you haven't tried before. I think you've built a dependency on the benzos so probably yeah good idea to get off everything and then just wait and build up again on milder stuff. Since at current rate you're at risk of just becoming more and more dependent and drugged up.