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?