Clean does not equal no or an easy come down- MDMA depletes serotonin more than any drug it may be cut with, so it stands to reason you may feel a bit down after.
I think you'll be fine- don't over-plan your spacing to much, and just go with what feels right in terms of re-dosing. I find the worst day is not the day after, but the day after that (Say if you roll on a Saturday, you'll be OK Sunday, then feel the crappiest Monday & Tuesday)
Also, I find the more sleep I can get after rolling the better- perhaps get a sleep aid (melotonin, valerian root, other over-the-counter drugs) 5-HTP afterwards helps many people tremendously, and is available at a lot of nutrition stores as well as Costco.