Summer shouldn't be that different from any other season in one's life; it was a huge shock when I first started working and had to go to work 52 weeks a year, summer not "off" :-)

I'd make a "schedule" for yourself, work on discipline and self-starting which you'll need to do well in your advanced classes here in a month's time? Make a schedule to work on each of your projects, maybe a different one each day? Also think of a list of things to do with the foster kids and "schedule" it so you have some sort of plan you can refer to if your mom or anyone "complains". The busier you "look" the more others will leave you alone? Just laying around on your bed doesn't get anything worked on and isn't very satisfactory in its own right?