basically I have the exact opposite problem as Elmer Fudd. And it's often at the beginning of words too,
like this one awful job interview I had a while back the lady interviewing me thought I said "reekend" or something instead of "weekend".
my new speech therapist pointed this out too. She recommended I form an "o" shape with my mouth and that kinda helps, but it sucks having to consciously think about this lol, and I'm having to work on other sounds at the same time too. :\
I can't find anything on google for this either, lots of results for "rhotacism" but not the other way 'round...