Could you please post a screenshot to illustrate the issue?
What is the file’s resolution (Image > Image Size)?
The largest UI Text Size setting isn't terribly large. This illustrates the full range of sizes...
It might help if you'd describe your system, and especially the display characteristics. If you have a high dpi display, another different setting in Photoshop CC 2014 might help you - in the Experimental Settings preference panel you will find a Scale UI 200% setting that is made for displays with 200ish pixels per inch. It makes EVERYTHING big.
Edit: On re-reading your post I may have understood you completely wrong. It sounds as if you're trying to TYPE text into a document, in which case your document's pixels/inch setting will influence the point size. You can specifiy the text in another unit (e.g., px) or you can reconcile your document's point size, which is what C.Pfaffenbichler is saying above.