I love Greek yoghurt so I'm probably not best placed to advise ha ha, but it does mean I use it a lot
Lots of good sweet suggestions here but have you tried incorporating it in savoury for instead/as well?
Do you like sour cream etc dips? I often mix it with coriander [and lime - but this might make the sour issue worse] to make a nice dip to go with e.g. Mexican food, or grated cucumber and mint (this is my favourite) to make tzatziki. Lovely with salad, kebabs, etc.
Also I make fresh coleslaw using Greek yoghurt instead of mayonnaise. Just grated carrot, finally sliced onion and cabbage. That might work for you if you don't like the texture - you can dollop it all on a baked potato for a lovely coleslaw with tonnes of veg.
The key to all three of those is SALT. Adding salt, a little to start with and adjust to taste (as well as pepper if you like it) evens out the tang.
The overwhelming flavour you dislike is the sourness/acidity, so that can be balanced with sweetness (PPs' suggestions above), fat (like adding olive oil but I'm guessing that's a no no), salt (my suggestions above) or heat (adding some chili would distract from the sourness but I don't think that's the answer for you for some reason lol)
If all else fails just stop eating it, food should be enjoyable x