Lump under jaw

Sounds like a lymph node. You're probably right that it's from treating Bartonella. Red root can help keep lymph moving. If you feel like you can see a professional in-person safely, then craniosacral therapy is great. YouTube has some good videos for self-administered lymphatic massage for the neck and head.

Other possibilities are a dental infection or virus, but in the absence of other symptoms, my money is on treating Bartonella.

I would have it checked out too

I have had a lump like that in the past - was no big issue - a blocked pore had caused a hard cyst - but needed to be surgically removed

I developed an enlarged lymph node under my jaw when I first became infected with Lyme + Co-infections. It never went back down in size. I got a CT contrast to make sure it wasn't cancerous. Came back negative.

It's about the size of a pea. I can only tell it's there when I lift my head up. It doesn't move and never went down.