Pwobwems aw over the pwace!

Hello, and welcome to Speech Impediments R Us! I don't know what my problem is lately, but for the life of me, I cannot say the letters L or R. If I'm just talking to someone, it's fine, but as soon as I start reading a cast, I get all fucked up. The more I try and concentrate on getting the words right, the more I screw up. I sound like a fool. A FOOL I TELL YOU! Blah. I'm going to have to go back to doing Sammy the Snake exercises or some such thing, aren't I?