Stickiness remaining after removing a plaster

Q: Due to a small tiny cut on my left knuckle middle finger I put a plaster on it, I removed the plaster afterwards and washed my hands but realised later after that there was still some residue of the plaster stickiness/glue left so if you rubbed it off it would form like a sticky rubber effect. Because I may have washed impure hands afterwards whilst the stickiness was there and not realising and then wiped them with a towel, I am concerned impurity may have been spread or would be pure as I initially did wash my hands but did not realise the stickiness was still there. I am a waswas sufferer and I am getting better everyday with the help of the almighty therefore I am always very concerned on purity as I always think I am spreading impurity everywhere.

Masturbation

Q: Whilst I was doing some work, I got aroused. I tried to ignore it but I was feeling overpowered. I held my private parts and squeezed my legs trying to kill the feelings but it made it worse. I was sitting and trying to ignore it but I ejaculated unintentionally. Am I sinful for this action?

Tawbah

Q: A sister wants to know if she got caught out sleeping with another man few years back and she truly is sorry for this act. She has repented. How must she make amends so that Allah Ta'ala accepts her repentance? Must she make tawbah everyday? How must she make amends with her husband?