I would like to offer you a little piece of advice if I may. I personally think you are making the classic mistake of almost everyone in our age group who hasn't worked out in a long time and wants to get back into shape.
You have no patience.
Working out 4 or 5 times a week is way too much for an untrained and aged body. You are trying to make up for all those years of abuse in one quick swoop. This is precisely the reason you are sore and this is the reason you will quit.
Move into this SLOWLY. Work out as a beginner no matter how fit you use to be. Forget your ego. Read and read some more. Get your diet in check as this is as important or maybe more so than the workouts.
Make this your new lifestyle - and balance out the workouts; the rest; the diet and the supplements.
Remember that our age you are only doing this for yourself.