Thank you for your question, Karen.  Your plant appears to be exhibiting the long term effects of inconsistent pruning, which should be done in early spring every year.  You want to make sure that you leave a growth node--where leaves come from the stem--because totally woody tissue will not grow stems or leaves.  Typically, you can godown to 6-8 inches maximum.  But that may not be the case with yours.  You will not help the plant by pruning away anything but the clearly-dead stems in this hot weather.  It just creates wounds from which moisture escapes.  You can water it during hot periods, so long as the soil drains well.  Otherwise, just leave it alone until spring.  Good luck!

Welcome!