My parents are going out of town for couple a days. I usually took full advantage of that in the past(like:masturbating every time i saw someone sexy on tv, waste my time on too much gaming,etc). But now, i'm totally set on not wasting my time on these stupid habits anymore. I actually kinda resumed my art skills in this quitting time, and i enjoy the outside world a hundreds times more. If you face a setback don't worry, this whole community is with you and to help you. Just think of everyday you make it without PMO as a accomplishment and the moral boost you'll get is tremendous. Plus it'll help you to extend you streak more easily.
Don't take any chances, any library you can go to? And any close relatives you can stay with at nights? I would definitely do that if I were in your shoes.
to expand on this and hopefully help someone else in need, redirect your focus onto something else. do a pushup, go outside, anything other than give in. in the 90 days you'll have plenty of time to figure out what works best.