Doubts with regards to mistakes in Salaah

Q: I have constant waswas.

1. When I am reciting suras in salah or reciting tashahud sometimes the letters do not come out loud enough so I can hear. Is my Salaah still valid?

2. If I make a mistake in reciting in Salah how far do I go back to correct myself. Do I restart from one whole verse or just from where I made the mistake.

3. In tashahud I didn't say "warahmatullah hi barakatu" properly, so I went back to that bit and recited it again. Is the salaah valid?

Domestic problems

Q: I am having difficulties. I am divorced for the passed six years with 3 kids. I don't have any help from my ex-husband for the kids and I have two brothers. My parents and brothers have hated me a lot. In the passed three years we have become enemies. They don't like my face. They mistreat me and don't let me go to work. All my ways are blocked. I need a wazifa. I want to get a job and they must all agree like before I was working. I am suffering a lot for the passed one year.