Kids getting too frustrated?

I am so bummed out that I had two students (6th grade) drop out of my SCRATCH group. We only had a few lessons and they just gave up. :( I am talking with the rest of group (6 of them) and trying to get their feedback about it and I htink the rest are in but still I am reevaluating what I can do to not make this so overwhleming. I am using the Curriculum provided by MIT but I do not have enough time to do the entire lesson at school (I see them every 6 days for 30 minutes) so I use Edmodo (web app) to deliver some of the lessons. I have explained to them that it is like learning a new langauge and you cannot expect to learn Spansih in one day--so just be patienct and it will come! I had them use the All About Me page for guidance on next lesson and I am not going to push them too much with completing the design notebook. I do realize kids have a lot going on at heme and at school and because this is a pilot project it is hard to retrofit this into their busy schedule. Any suggestions or ideas will be appreciated! Thanks!