Kaffarah for breaking an oath

Q: I'm in a dilemma. Three years back, out of josh I made a bunch of promises to Allah and qasams. I have since done proper Taubah for this. I don't remember whether I promised or took qasam to Allah that I will study my books every day. But since then I did for a month and haven't been keeping that promise or qasam. What is the kaffarah for this? I'm really scared does this count as me breaking the promise or qasam daily or is it the Initial promise or qasam? I went through a very hard time because of these broken promises/ qasams. After my taubah I felt contentment and started practicing again. After my taubah I felt contentment and started practicing again. I know not to make the same mistake. Another qasam I made was not to do a particular sin I did that sin multiple times after that. What is the kaffarah?

Iddat

Q: I want to ask question about iddat. My sisters husband passed away and she is on iddat.I want to know about the rules of iddat, what to do and what not. Here all are saying to be inside her house without meeting anyone and should cover mirrors and wear only white clothes. She has 3 children who go to school and others have to be there to take up her duty on her children. Please clarify my doubts.

Being involved in a haraam relationship with a Hindu boy

Q: I love a Hindu boy and I had taken an oath of Allah to him that i will never leave him. But I had read in some Islamic post that pre-marital love is haram and we can't marry a non-muslim. He had promised me that he will convert but that conversion will not be for allah's sake. I am in a big trouble. Please guide me for this and also for the oath.