@Masemase, just wanted to offer a brief reply to your post. 90 mg a day of Adderall going into your system every single day does seem somewhat overdone, certainly by conservative standards, to say the least. If you're not getting very noticeable effects from that much, that's definitely concerning. 20 mg was honestly all I ever needed to get off my ass, and in retrospect, I'm sure 5-10mg would have more than done the trick - I was simply greedy. While physically tapering off would be the logical answer for you to get off that amount, and considering that you have been habituated to as much, I'm sure that would make the most sense to you too, nonetheless, if I just had to throw out advice, I'd say go cold turkey over the weekend, and, subsequently, resort to a very mild replacement, such as green tea, for example, for a few weeks, to help alleviate the wanting for Adderall. I don't know, I honestly myself don't even think that's offering much to you in the way of concrete help, just mainly wanted to comment that taking in that much Adderall for more than a decade (although it did sound like you've upped your dosage steadily over time, but you didn't give exact amounts, so I'm just offering broad conjecture), or, at least, by taking in 90 mg a day for presumably a few more years if you don't succeed in quitting, does seem like it would equal out to, while not leading straight to heart problems technically, the same long-term results to your heart as consuming very large amounts of caffeine or picking up a bad smoking habit, and by all means likely do as much overall damage, if not quicker and in more assured stabs. However, my long-term use of Adderall is rather minimal, but, personally, as a healthy, 20-21 year old male who worked out 5 times a week with muscle training averaging at 170-180 lbs for the majority of the time when I was on Adderall, it still seemed quite stupid on my part whenever I did over 60, or especially over 80, mg at a time - my times over 100 mg when taken together couldn't have been more than 10-12 times, I think, and, of course, that shit was just idiotic, and eventually made me want to quit drugs altogether, including caffeine. And that was with a young-ass body working that shit out of my system constantly.
Anyway, it would seem that, if you keep up on the regimen of doing 90 mg a day, I mean, where's that going to lead? Either to more of the same, which, even though it's not exactly in amounts which can definitively cause vasoconstriction with the heart, I guess (I don't really know though, I'm just mentioning that term), still, long-term, that's not going to do your body any benefits, by any means, especially with cardiac-related issues. And, the point of what I'm saying is that, if your dosage has been pushed up in the past...and you aren't really feeling the effects of 90 fucking mg, which is a large amount, then it would seem that your dosage may just be pushed up in the future, and I know for a fact that when you get into 100-120 - and, of course, though more extreme, to 150-180 - mg territory, that shit is just unseemly and unnecessary for productivity, for real. If I was a firm believer in sticking with stimulants of some kind, which I'm currently not at all because I think it's more reasonable to advocate abstinence from these substances, especially amphetamines, I would possibly say, at the very least, to switch to Vyvanse or Focalin, but, to be honest, I'd just say get out now with all speed, no pun intended. That's just my two cents, hope it goes well.
(Also, as an add-on, I really am not that knowledgeable of what the long-term effects on your body are from sustained Adderall use, I just know from what I've read up on the web, and it's usually not pretty - I understand, however, that most of these stories that I've read are from people who really fucked up with dosing, and just went on multiple, multiple binges. Of course, it does sound like you are sticking to your prescribed doses, which is a plus, but, seriously, especially since you say you want to get off it, I'd suggest reading around about the negative shit that can happen to your body from doing a lot of speed and amphetamines over time - if that doesn't make you want to quit permanently, I don't know what will - self-motivation when you realize life is going to happen anyway seems to help, at least it did for me, sorry if that seems like superficial advice).