Welcome to Ireland Reaching Out!
There are three RC parishes which correspond to Templecrone civil parish: Annagry (1868), Lettermacward+ Templecrone (1876) and Gweedore (1868). Co. Donegal RC parishes for whatever reasons have very late availability of records. So you will not find church baptismal records and civil registration of births did not begin until 1864.
I looked at the 1828 Tithe listings for Templecrone parish and did not see any records for Crohy townland.
You may want to consider autosomal DNA testing to see if you can identify a match who might have more information on your family. Autosomal matching looks at both your paternal and maternal lines.