I would not use Biofreeze on skin that sensitive. Also, it could absorb into your clothing and wind up where you don’t want it to go.
If you just ran your first marathon, especially at age 52, as a general rule you want to allow more time for recovery before racing.
I’m not surprised you are sore, but if you posted those times in that order, you will probably have no difficulty recovering. The irony is that it will take a lot longer if you hurry things too much.
My advice is to stick to some longer runs of 10 miles or less at an easy pace to keep up the circulation and aid in your recovery. Marathoning is not to be taken lightly. It should take a long time to train and a long time to fully recover. The best in the world will not compete in more than a few a year, and the average amateur athlete should not expect to do well in more than one or two a year, until the post-marathon soreness becomes less common.
It takes years for the body to edit out all the weaker muscle fibers and to tailor them to the type of exercise you do. Just give it time and you will do fine.
Meanwhile, you can find some other less-irritating ointments to rub into that area to look for some sore spots there. That’s assuming this soreness is not irritation from clothing that might be expected after a first marathon. It can take a while to edit your marathon clothing as well.
Best of luck in your recovery!