Cymru

Disclaimer: not at all fluent but spent about 3 years learning Welsh in evening classes.

It's hard to pronounce most Welsh words with an English accent. The place where you put the emphasis in words in Welsh is different to English. Also there are sounds which just don't exist in the English palate.

But on the other hand, sometimes it's easy to tell someone has an English-speaking accent when they speak Welsh, and I wouldn't worry about that too much when you are learning.

So you kind of have to pronounce it in a slightly alien way to English, but you will still retain elements of your accent for a while.

https://users.aber.ac.uk/jcf12/project/welshcheat/welshcheat.pdf

Interestingly, one of the reasons that some Welsh people sound so destinctively Welsh when speaking English may be down to how their community was taught to transition from Cymraeg to Saesneg. So maybe try to sound like someone from south wales speaking english?