First you will need to get over the embarrassment because at some point, you will need to use the voice in public. Part of the process is understanding that your voice will sound different to you that it will to others. A voice coach is one way to learn how to produce the proper voice if money isn't much of an issue. If you have had a singing background, it mostly a matter of using the head voice to speak in. I am also willing to work with people and am set up with Skype if you would like to receive help that way.
Once you understand the process and train your brain, it's not difficult to do but you are breaking the habits of years and replacing them with a new set of habits. This can take months to turn into a reflex action.