I've taken the prereqs. Just awhile ago. I feel like I know the basics well enough. I've just never applied the information in my prereqs like I"m supposed to for the MCAT so it's freaking me out lol
I was in the exact same situation as you when I started the SN2ed schedule: I graduated in 2011 and for various reasons delayed studying for the MCAT until mid May of this year, so it had been years since I had seen the material, and the first few weeks were absolutely brutal. I didn't remember and/or know what specific gravity was, what a mole was, what a cation was, which direction water moves in osmosis, and on and on... it was pretty rough. I also felt like they were assuming knowledge/tricks/formulas that I didn't remember, couldn't relate to the material, or whatever, and frankly I just got super depressed. One thing in particular about the BR material is that the earlier chapters actually DO reference material/equations/concepts you haven't seen in the BR book yet; don't worry, they'll cover it later. I don't know why they do that, but it freaked me out at first until I kept plowing through the chapters and realized that if something ever comes up in those books, it's GOING to be covered, just maybe not in that same section or chapter.
I honestly felt like giving up, but I just tried my best to keep up with the schedule, and even though for the first 6 weeks or so it felt like I was barely keeping my head above water, I started taking full lengths about 5 weeks ago and have scored between 31 and 35 on the AAMC tests. Just keep going! I don't know what your target scores is, but trust me: when I started studying I thought I was a hopeless cause, and now all it seems I'm doing is rescheduling time and again, chasing higher and higher scores. If I got this far after 3 years away from the material, so can you!
Stay strong mentally and physically: eat healthy food, get 8 hours of sleep, exercise regularly, pray if that's your thing, and get in a routine so that you don't have to make decisions about what comes next in your day, and don't let your social life mess with your routine. Also something that helped me de-stress was letting a day's work stretch over into the off day if you feel like that's needed. Don't compare your progress to other people if you can avoid it, just do what YOU need to do to keep going, and if that's pushing certain parts of the schedule into different days, or swapping assignments here and there, do it.
Also vodka. Vodka helps.