I am in constant fear.

Have ideals. Shri Ram's struggle, Jesus's struggle anyone you have always admired.

And promise yourself whatever happens you will not let them, their teachings, theirs struggles down. They led a remarkable life and they would like to see you face your battles as well.

If can't find anyone of those likes, look toward mortals. There are great men all around us. Heck, even the pan masala endorser SharukhKhan made a fortune without his father and is now an inspiration to many.

You know things do get better. You ll find experiences in your own life if you look back.

These are just phases which life(ideals) test you upon.

Jot down point and paste it on your wall. Don't let these comments be a One day motivation/ clarity.

How many years of experience do you have?

I can completely understand how you feel. I have a few suggestions to reduce the anxiety a bit:

(1) Financially: Save as much money as possible every month. Keeping a fund with 8-12 months of runway will go a long way in reducing your anxiety.

(2) During Work: Try your best to keep learning and growing. Build context of your systems, go through that big file of code you're afraid of reading. Share this context with others and use it to solve issues or suggest improvements. Impress with your quality of work and try to be on good terms with your manager and coworkers.

(3) Outside Work: Keep some time aside every week to passively prepare for interviews - DSA, software design, system design etc. Keep your resume up to date and always ready to go. This will give you some confidence to be ready to crack an interview as and when required. Every 3-4 months, apply to a few places just to interview passively.

(4) Mentally: Adopt the philosophy of stoicism. Face your worst fears and try to think of ways to deal with them.

All the best!

Put effort on being top of your work. Focus all energies there. Be in sync with your manager ask for regular feedback . Take upskilling courses if needed. Seek mentorship , many people will be happy to mentor you.
The bar of good workers in India is pretty low. I'm sure you won't lose your job if you work well. And even in worse case you do..you would have learned a lot by then that you can easily a good job elsewhere. There is no dearth of jobs for people who are great at what they do. So focus on becoming great.

There are things in life you can't control. List down the things you can correct and improve and act upon them. Too much of thinking will lead to unnecessary headache and health issues

Relax. There are people doing worse and be grateful that you have a job. Pray and remain strong for your mother's and sister's sake. Keep upskilling yourself on weekends or when you find time and work hard at your job. Remain grounded and keep faith in life. You are not the first one and you will not be the last one in this hard situation. People always find ways to pass through struggles. Life has to go on. Stay strong and do your duty. Avoid medicines to the extent possible. Cook humble food at home if possible and save your money and health.

Some excellent points mentioned already. If you truly believe you're good at something then go ahead and try to create a second stream of income, provided you have the time. You can always network and take up freelance projects that will keep you mentally occupied outside work, and will also offer you a financial backup even if the worst happens at your workplace.