All LP (Lightning Process) seems to be is saying motivational statements, not allowing yourself to think about "bad" or "negative" thoughts like having symptoms or being sick (even if this is reality), and deciding to think (er, being manipulated into thinking) about yourself as healthy.
Plus there may be some kind of gag rule (if you don't like it, you may have to promise not to tell others, and even if you do like it, you might not supposed to say what the protocol is).
It seems to me that LP would interfere with managing symptoms. Just because you notice symptoms (I am having x symptom) is not a "bad" or "negative" thought and is necessary to figure out what to do about it (e.g., normal symptom hungry--> may be eat... disease symptom lightheaded-->may be drink and lie down).
Simply denying symptoms would be creating a false world. Lots of people try this--normally when initiated by the patient it's called denial
and denial is considered not the best coping strategy in the book to carry out long term, but it's normal, most of us have been there at some point, sometimes off and on--certainly that was my main strategy at one point when I wasn't diagnosed and the doctors had no clue what to do and neither did I.... but it probably made me worse.
However when denial is specifically induced by the therapist as if it were a treatment, I would think that would be profoundly unethical.
So if you want someone to talk to, you may like to find a support group or get a recommendation for a good supportive counselor. There is no good evidence cognitive therapy can help your disease; it could help your coping and quality of life, if that's what you're looking for help for.