DH and I use English at home. I do know Finnish quite well, but since our relationship started off with English, we've just never really switched. I do speak to his parents in Finnish these days. And I do have some friends that I speak only Finnish with. It's sort of a mixture of me speaking Finnish and English, depending on the situation, but mostly English.
I totally understand how you feel about speaking English because the relationship started off in English.Ours did too and it’s been so many years now of speaking English that when we do switch around it's odd. Thus why we stick to English in the house I guess. : )
We live in The US, DH is American and I am German. We speak German in the home most of the time and I speak German to our son almost all the time (even in public). I sing to him in German, read to him in German etc. There are days when DH and I do speak English to each other though - out of laziness. ;-)