Hi last year I was assured that since my SS Disability isn't taxed and my small spousal support isn't taxed I do not need to file for 2018 tax year. Is that correct?

You need to file a federal return if half your Social Security plus your other income is $25,000 when filing single or head of household, or $32,000 when filing married filing jointly, $0 if you are filing married filing separately 

DO I NEED TO FILE A TAX RETURN?

https://www.irs.gov/help/ita/do-i-need-to-file-a-tax-return 

Who has to file?

http://www.irs.gov/uac/Do-I-Need-to-File-a-Tax-Return%3F