Don't beat yourself up!
I've got 11 days since the last time I used coke, and about a week since I drank. If someone I knew and cared about (or realistically, anyone) showed up with one or the other, I might have a hard time refusing - and I'm not on pain pills either.
Do NOT beat yourself up! You've done the hardest part, and that's deciding to make your life better. Your doing this for you, not for any of us. You'll do better next time. Every day you don't use - every second you choose to do something for you, you win.
You need to take care of you, and use your recovery as an excellent excuse to keep yourself away from those who would undermine your recovery. Your uncle is obviously not concerned about your recovery - most active addicts won't be - you're making them look really bad. Good luck!