Suggest Remedy For Difficulty In Pronouncing Certain Letters

im 45 old having s problem of speech seems half of my tongue left side wont work when i tried to speak letter R and L, thats my problem since i was a kid. when i was a kid was my father dont want us to say anything when he got angry he wants us to be silence all the time and maybe thats the main reason why im having this problem. can u advice me an over the counter med to help my speech problem, i need your prescription doctor because sometime i ask to be a speaker infront of a congregation. i anticipate your help and thank you so much doctor. God Bless you