Suggest Treatment For Forgetfulness And Poor Concentration

Question: Hello, I've been prescribed adderall for about a couple months now. In the past, I've had some trouble with comprehension where I'd have to read some things over and over again and struggled even more to follow what a class teacher was saying. I've also lost things and forgotten things very frequently. However, I've never really been hyperactive nor have I had too many rushing thoughts during a class (both of which are common symptoms of adhd). Instead, I've struggled more with low energy, especially mental energy, many times in the past. I'm unable to find pleasure in many things, including social activities. I'm sadly on the autism spectrum as well, so I'm guessing that's the cause of many of these problems. I was first prescribed 20 mg a day hoping to help me in these areas. When first taking it, I was high as a kite for about 3 hours, then felt completely hungover during the comedown. So apparently, I'm quite a light-weight; possibly either from the fact that I have a fast metabolism or just because my nervous system is really sensitive. After about a month later, I started taking it again, but only 5 mg throughout the day. On this dose, I've been able to work on my homework a little bit longer on it, but have had the following side-effects: on the first day, I felt mild mood swings (a little euphoric and a little agitated). By day 3, today, the mood swings have largely subsided. Occasionally I would still feel little bits of pleasure and optimism; don't know if that's necessarily a good thing though because I know it's artificially induced. For the most part though, I now feel even more apathetic, more fatigued, and more disconnection with the world when on it; I could sit at a chair four up to three hours and feel content doing absolutely nothing. What I would really like to know is if these side-effects will all go away if I stay on this drug and let my body adjust, if I should be taking this drug everyday or just on an as needed basis to get its maximum supposed benefits, or if I should even be taking it at all. Will this drug enhance my ability to enjoy the things in life, or completely ruin it?
Thank you for your time.