What tech other than web dev can I learn to get completely remote work?

Apologies for brining in a personal situation, I am a developer from India with Crohn's disease, things got really bad lately and I lost my job. My doctors say I need a proctocolectomy. Reading experiences of others who have undergone this surgery it would be quite difficult to hold a office job even after recovery as roads here are really risky. Since ostomy supplies required for day to day life are not covered under insurance in India (approx 350 USD/month) I cannot rely on freelance gigs alone.

My present skills are Java and Spring Boot backend development, I am learning React & Google Cloud.

Could you please give me some advice on technologies / programming languages / skills other than front end dev that I can learn to increase my odds of getting completely remote work.

I can invest upto $1000 this year to learn new technologies / skills and am willing to work without pay for a couple of months once I am back in the job market, to find a completely remote job / contract.