Working from home due to financial constraints

I am a young sister in Islam who has been going through many trials over the last 8 to 10 years. Amidst all of this, I seek comfort that Allah Ta'ala will one day ease my difficulties. A Summary of these trials, my mum has been battling a fatal illness for many years. Together with my dad being very ill, I lost my father two years ago. I am currently not married. With my mum's illness, she has been in and out of hospital, leaving me to dwell alone. My question is:

1) I have no one to support my mum and me and hence I work in an accounting firm. They allow me flexibility, so I work certain days from home and certain at the office. Please advise if this is permissible in Islam?

2) I own a credit card and very rarely use this. Most of my purchases are made on cash. Please advise if this is totally not permissible in Islam (meaning to even have one in your possession)?

Maaf for these questions, reason is I feel as if though my trials are getting harder per the day, affecting me emotionally with loneliness and much more. Hence I fear I may be engaged in some sin that prevents ease at home and opening in life for nikah and betterment in this world, which has prompted me to query the above two questions. I am currently fully in hijab and strive each day to be a better muslimah. Kindly remember me in your duas.