Here are the sounds I have trouble pronouncing clearly: s, d, double t's, th. I went through speech therapy and I improved over the first 6-9 months and I was fitting with a mouthpiece, similar to a kid wearing a retainer after braces. It is thicker which gives my tongue something to touch when I talk. That has helped as well. I don't go therapy any more; I guess they believe it's not a problem. People say it's hardly noticeable but to me it's pronounced. Speaking... speaking Spanish, more specifically, has been my life for as long as I can remember but now I can't do that as effectively as I once did. That just kills me, figuratively speaking. I have never been the most social person either but now I sometimes I withdraw from social conversations for fear not being understood.