I experienced the same things at almost the same timing as you. The chest pain was a pulled muscle untouchable from the outside but once I moved my head down and to the right to kiss my husband while laying on my side and the pain was reproduced. That's how I found out. It has gone away with time but can come back. It's right in the heart area and travels to the left neck sometimes. It has gotten better with upper cervical chiropractor.

I also had breathing issues and it was anxiety some I brought on and some what mark describes. Has subsided greatly. I do breathing exercises to relax my muscles.

For the muscle twitches and tingling of nerves (mark thanks for explaining this so incredibly well) I take gabapentin because for me it is much worse at night. I believe this is subsiding but can come back with stressful times. Also had tinnitus that came and went but that is gone now.

All this being said (I'm almost 6 months in) I have had symptoms reappear due to driving too much and the stress of the holidays. Just last night I had stressing out about holiday plans and my muscles started twitching.

Finally the headaches - mine changed like yours and I'm almost positive they are neck related as mark has advised me. It's been a long process with those headaches. Someone hugged me wrong last night and a headache came on strong and I still have it.

Happy holidays - wishing you the best and glad things are looking positive for you.