I have ADHD, chronic depression, and OCD. I have 10 years to learn how to make cheap substitutes for Provigil, Fluvoxamine, and Strattera. Then again, I have 20 years to learn how

All three conditions have been implicated with an underlying cause: poor nutrition and environmental toxins. Post-peak, if you are eating at all you almost certainly will be eating an unrefined, unprocessed diet from food grown without the use of poisons and sprays. Chronic depression, except in rare cases, responds very well to the same unrefined, unprocessed diet from food grown without the use of poisons and sprays. (Not necessarily a cure, but relief.) Unfortunately, despite it's simplicity this is a difficult diet to adhere to but if you are mostly successful you may see relief, and at least it will help you learn if this is a factor for you.
Be forwarned -- moving to this kind of diet tends to make you feel much worse for anywhere from a week to 2 months, depending on how bad your diet was before.
Environmental toxins are harder to pinpoint, and won't simply go away post peak -- in fact, they may get worse for a while. Careful research of the level of toxins in the area you plan to settle in seems warranted especially in your case.
St. Johns Wort does work well for many people, but it uses the same mechanism that commercial anti-depressant drugs do, namely it's a serotonin uptake inhibitor. Many people have depleted and exhausted serotonin production, from years and decades of processed and high sugar foods. (These foods cause a temporary rush of seratonin -- a feel-good neurotransmitter -- and eating too much of this crap literally wears your production system out. We call 'em comfort foods for a reason.) Do not take St. John's Wort while taking any other anti-depressant!
Other that completely revising your diet, you can help improve your serotonin balance by avoiding tryptophan (in many protein rich foods, especially poultry -- it causes a seratonin rush), avoiding all sugar (also a serotonin rush), eating 5-6 small meals per day made up of fat, protein and carbs whenever possible, and increase your intake of foods high in vitamin B6, which aids in healthy serotonin production. Omega 3's are also believed to be helpful, but I would limit fish sources of Omega 3's in your diet, due to the high levels of chemical toxins frequently found in fish, since it may be a factor.
Low dietary and blood levels of all of the B vitamins have been implicated in all kinds of mental illnesses. Natural sources are best, but you may want to try taking a high quality b-complex supplement (at least 200%+ of RDA) for 3 months to see if it helps reduce your symptoms.
Finally, low-level food allergeries are also a trigger for OCD and ADHD. Consider asking your doc for a full blood food allergen screening (ELISA). They are fairly expensive, and can give false negatives if you haven't eaten that particular food for several weeks, but positive results are very accurate and if may help you pinpoint a big problem. Unlike skin tests, there are no tedious and painful visits to the doc -- just one blood draw. If you do show a big allergy, your doc will likely suggest completely removing that item from your diet for 6 weeks and then performing a challenge test under medical supervision to confirm the allergy.
It can be very hard to gauge the effects of dietary and lifestyle changes when you are taking pharmaceuticals. Depending on the way you manifest your symptoms, you may be able to be fine without your meds, but I would try reducing them one at a time and only with the supervision of your doc. If your doc says it is safe to try tapering off and eliminating the drugs before you try any of these things, that will help you pinpoint what will and will not help in your particular case.