If you are able to speak, but only quietly, have something with which you can make a noise, in order to alert people when you want to speak. Some telephones can amplify outgoing (or incoming) sound.
It may be worth learning a bit of sign language or inventing some signs of your own. A speech therapist may be able to provide more information or equipment e.g. a computer. Computers can provide an artificial voice if you are able to use one. Some people communicate by blowing or moving to indicate each letter, while another person says the alphabet. It is more efficient if the alphabet is ordered so that the most common letter comes first. Here is one such English language ordering: e t a o i n s r h l d c u m f p g w y b v k x j q z. Other people trace letters with their finger on a helper’s hand. Alternative methods of communication include boards (bought or home made) with pictures, words, symbols or letters. The person who is ill indicates either by pointing, moving their eyes or making some signal as the helper points. However, some people with M.E. are too ill even to do the thinking required for communication.
Computer : Reading : Telephone : Writing