If my only income was $1050.00 a month alimony for the last 5 months of 2019 do I have to file taxes? Also I can't get a stimulus if I don't file?

I haven't worked for 17 years, my husband left me and I received alimony for the last 5 months of the year.  Just found out my X filed seperately and didn't include me.  I can't get a stimulus unless I file?