Pest infestation left my plant folded and weak. I treated it, but now blacked out leaves?

I think your combination of things upset the plant. Normally Neem is enough. I have not heard of Cigarette Butt tea before. I understand how nicotine is an insecticide but the rest of the chemicals in cigs are fucking disgusting and then useing the filters that capture them all and making a tea out of it. Yuck.. Unless your using pure tobacco from a rolling shop don't do that. You can also sometimes find something called Grabba in Jamaican communities that might work. IDK how stable the nicotine is after fermenting and drying the leaf so just look it up but its also tobacco. The garlic depending on its form. fresh, freozen, powdered can work on some pests but its not all that effective. I would not use this again. Soap/dish detergent is ok as a topical thing in a mix of stuff, they normally add this for the sudsing effect it offers to cover the pest, it also is good that it is a degreaser and can dissolve some of the protective oils on bugs and that kills em. If you only want to it break the water tension then using something like Yucca, more plant friendly and also froths up. Dishwasher soap as in for dishwashing machines is not good. that stuff is quite alkaline and can damage things easily. Ants normally farm aphids as their sweet secretions they make called honeydew are quite tasty to them, Ants will also protect the aphids as its a mutual relationship. Imagine something eating your shit and guards you while you eat in a hostile world. Amazing. Soap and water will kill of aphids just fine. You can also power blast most of them off the plant with a water jet. Best to get pics of these pests and not old world methods when dealing with pests and plants you care fore in 2024. might end up killing them or toxifying the soil. Good Luck!