I'm assuming you have your DNA tested and you have your autosomal DNA and perhaps your MtDNA. And I take it to mean you have no brothers or sisters. With no brothers or sisters you will have to look at your uncles, aunts and first cousins (or their children) on either side of your family and ask if they will do a DNA test. I see no point in testing family with private or anonymous profiles since no-one on WikiTree will be able to see them although you can always add their results to GEDMATCH.
Failing that you will have to go back to your grandparents and research their descendants and their siblings descendants looking for someone who is interested in DNA testing and will be willing to test.
I hope this helps.
P.S. I've just looked at your profile and you've already done the testing. Perhaps you should get the MtDNA test from FtDNA as well.