You are right about changing form. It is known as L-form. That is the persistent form. Part of the problem is that it does not always do that. So many many people (and the Dr that treated them) see the Lyme that just was easily killed by the antibiotics and they think that the people that have the persistent form are crazy or wrong. Add in the over-reaction by the immune system in some people and you have two forms that can lead to lifelong illness. Like leprosy or TB.
I think the important takeaway is that if someone has Lyme and a short course of antibiotics does not kill it, seek a Lyme expert. Not just an infectious disease doctor. A Lyme specialist. And do it sooner, rather than later.
I am certainly no expert on Lyme disease or human medicine. Just pointing out that some people do get over it quickly. And pointing out those that don't need to be their own advocate and not to just accept what they are told by someone with little experience with complicated Lyme disease (including CDC recommendations).
Sorry you had to go through this. I have two clients that have had it (the long or persistent form) and one of them was very sick for a very long time. She is finally on the mend after years of not aggressive enough treatment.