I was only on two antibiotics at the same time, and didn't have the kind of discomfort you report.
Ask your doc what can be done, whether other treatments would be less problematic, etc.
Also I would NOT take any herbals or medicinals or anything in that frame of reference UNLESS your Lyme doc okays it as to what meds/supplements you take at what doses for how long. Herbs and pharmaceuticals are all just chemicals, and mixing them without a doc's okay is just asking for trouble.
On another note, doxycycline and omnicef are not meds I took for Lyme and babesisos, so I don't have any idea if that is the best medication approach. I have read that if doxy is given VERY soon after the initial infection, it may be effective to kill the Lyme, but many of us don't know when we were first infected. I am not up to date on what the current meds are commonly used, but others here may have comments about their experiences. (My only comment about doxy is that it I have read that doxy is generally NOT useful against Lyme unless almost immediately after the infection occurs. You may want to get a second opinion from another Lyme doc, and you don't need to tell Doc #1 that you are getting a look-see from another doc. Just take copies of ALL your tests from the current doc to the second doc so the second doc can determine if the treatment is working for you.
All very cloak and dagger, but hey, it's you that's suffering! Best wishes --
I just got Dx with tendinitis in my knee, ankle, both hips and shoulder. The joint supplements they gave me don't help either!! And the B12 just gives me an awful headache. So your not the only one in that.
Did you find anything that worked for the pain in your tendons? I have had Lyme for 3 months. The doxy took away the rashes that were circular and bruise like but the tendons pain and random pain spots in my legs still remain.