Tapering the training before the race

So last weekend as you know now, I ended up doing 2 back to back races. A 1oK #NightRace followed by early morning 5K #YorkvilleRun. Both races were good and I did my PB in both. But now I can feel the symptoms of burnout. my Ham strings are like a Rock now so I am over using my Quads. This could soon go down spirally and end up preventing me from completing my half marathon #STWM.
Here I am in week 12 of training and I was struggling to finish my 5K tempo run and I am seriously thinking of resting for a week. Its like catch 22 if I stop I might not be able to catch up and if I don't I wont be able to finish the training. I finished it and used the foam roller and hope it helps to make it better by tomorrow.