Ok well first off, hit up a research chemical site, that is legit and has goos reviews on forums, order some clomid (nolva if you have gyno at all) and dose it at 50/50/25/25.
Next eat your ass off man. I tend to not eat alot some days due to my busy schedule, but i try and manage it all out. Id say buy a good weight gainer as well to get some extra calories. Hell eat a little dirty if you have too...slap some cheese on things, etc. Bottom line, Due what you need to do to grow. in 3 weeks of SD you shouldve gained at least 10-15lbs. Just remember man, eat like your a starving ethiopian.