If you drop a dose straight all at once like most people do, usually between 30 min and 1.5 hrs from you dropping it, you will start to feel tactile enhancement, clammy hands, more talkative, then after another 10-30 mins of that BAM you are basically absorbed in it from then til 3-4 hrs later, the speed at which this happens seems to depend on your metabolism or stomach contents i guess (you should always not eat for 3 hrs at least before dropping to not lose any effects). It's before that initial clammy hands period that the anxiety was bad for me when I first started using MDMA, its just the anticipation of waiting for it to hit BUT i think the drug itself does have a roll to play in causing this effect from what myself and many others have experienced. it was after I'd used MDMA a bit more that the anxious period started being longer, lasting up til it hits you full on, I don't know quite why that is though but I know many people report it.. its much worse if you dont have anything to distract you during this period, i.e if youre not in a party setting and are focusing on the drug experience itself. id say as its your first time though just drop it all at once and youll be fine, make sure you take enough for a full on experience but not too much.. 120mg is about right and personally I find redosing dumb, it should be treated like any other psychedelic i.e dose, come up, plateau, come down. if youre interested in how to smooth the come up then you can dissolve the dose in water and drink slowly over 30 mins, this makes it come on gradually a little like alcohol, does weaken the peak slightly though