Skin Infection - Cellulitis

Hi there...

I recently had an accident on my chin. It was a wound that required stitches. Then I noticed an Infection coming on around the wound. It was red, very painful, Inflammed and so on. I went back to my doctor who in turn gave me anti-biotics that contained penicillin that didnt help it at all, in fact it got worse and spread right around my chin.
So I went for a second opinion to another doctor. he told me it was the skin infection Cellulitis and He immediately gave me an Intravanous and Clindahexal (clindamycin) and Bactroban topical cream. The clindahexal is a very strong dose (8 a day) at a 12 day course. I saw rapid results from the IV and the healing of the infection slowed down drastically a day or two later.
So I went back and got another IV and a 3rd one the following day, as it was showing rapid results. (Whilst still taking the anti-biotics and using the cream.) It has now been  2/3 days later after the Intravenous and chin is looking much better but has started spreading by my neck and a little on my chin again.

What can I do now? Am I immune to the anti-biotics as I have read in many places is common?
Apparently there is an anti-biotic that is not resistant to the bacteria causing the infection called Zyvox. Is this the recommendable solution as the money I have spent on this is exhausting! And the 3rd opinion is needed here!!!

Please could u email me back asap!

Kind Regards
Shorty40