Even though you had taken 20 mg of Adderall at one point, the time off and the new medications you’re taking with it would necessitate starting it like new, which means starting at the lowest dose and only increasing if and when necessary. Being too mellow sounds like too high a dose, which is possible given that you’re taking different medications with it now.
There are two types of stimulants: amphetamine (Adderall, Vyvanse, Evekeo…) and methylphenidate (Ritalin, Concerta, Quillivant…). Almost everyone does well on one type or the other, but not both. It could be that you would do better on a methylphenidate.
ADDitude Community Moderator, Author & Mentor on Parenting ADHD, Mom to teen w/ ADHD, LDs, and autism