Problem with App Store

Hi! I am from Ukraine, now i am in the UK. And sometimes i can’t download the UK apps, because how i understood i have ukrainian account. I tried to change region in settings. It was done, but app store send me this message: „Account Not In This Store

Your account is not valid for use in the

UK store. You must switch to the

Ukrainian store before purchasing.” and after i it send me back to ukraianian account. Help me please, because i can’t download important apps.