Can't really advise on the CC but my LO was exactly as you have described at 5 months, we just went with it, yeah it was endless and lasted around 5-6 weeks but we got through it. We took him into bed with us and he settled no problem after that. I was concerned that he would get used to it and not go back into his cot but he went back into his own room when he was ready and sleeps through in there no problem now.
Hmm that's interesting, maybe just a phase then you think?
I really don't know hun, I can only tell you what my experience has been with my LO, as we all know they are all very different! But yeah, for Stephen I think it was the 4 and 6 month regression/growth spurt merged into one! I may be wrong but that's what I think. I know that if I had left him to cry it would have solved nothing during that time as he wasn't not sleeping to be bad, he just couldn't for whatever reason. It was really tiring and frustrating but like I say it passed.
Now for you I don't know if it's the same thing and I am in no way judging you, I'm sure you are a fab mummy but sometimes there can be other reasons behind their behaviour... not that I'm any kind of an expert!! lol
The best thing I did was decide to chill out, go with the flow, do what I had to to get a sleep and think he's not going to be a baby forever and for me that was letting him into our bed for a few weeks, in the grand scheme of life it's no big deal. For you it might be CC, do whatever gets you by!
Good luck and let us know how you get on whatever you decide x