I was closing the nipple on the left rear tire and the thing broke. The nipple broke off but so did the part with the bolt on it. I don't realy know what to do. This is really gonna set me back. What should i do next?

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W126 1983 300SD 286,000 miles and ticking
Baby blue exterior Grey MB tex
Recent work:
Replaced air cleaner mounting brackets and heat shields
Replaced alternator, fan and power steering belts
Replaced positive battery terminal
Replaced negative battery terminal and cord
New Duralast Battery

My car needs work.