migrated in Gst but turnover less than 20 lakhs

I have a sole proprietorship firm registered under dvat.

My nature of business is tiffin services. I have a turnover of Rs. Five lakhs p.a.

Recently its migrated to GST portal and GST registration number was generated.

should i cancel Gst registration or continue with Gst?

if i cancel Gst registration then my proprietorship firm exists or not?