OK, I learned about music in the womb so what works for me may or may not work for you - are you an ear person? Because really, finding a recording of the chant that you like - you MUST like the quality of voice and feel comfortable with the rhythm, so you'd probably want a slow one to start - finding that recording and singing along with it is the second best way to learn. Chanting with a real live person is the best way, but hard for someone with CFS unless you just happen to live with one!
There are a lot of online resources for recordings, so you could shop around without ever leaving your house. Or you might find one on YouTube that you can use: just search on the chant phrase at the YouTube site and see (or listen to) what you get. Even if you play it in the background while you do something else, it will be going into your head. You know how you remember obnoxious commercial jingles? A chant can get in your head just the same way. Just let it.
Music's all about the ear and the body, and about how things feel. The intellect can help, but it's not the primary source of musical knowledge. Music goes much deeper than that.