I'm going to guess (I don't have any medical training) it's not a stress fracture.  From what I understand stress fractures tend to have increasing pain as an activity goes on.  So if you said it feels fine when I get up but hurts more as time goes by - then I might think stress fracture.  Pain upon initial movement after long periods of non-movement (i.e. sleeping)  which then feels better sounds more like a tendonitis or other soft-tissue problem.  The area where you're having issues is generally where the Peroneal tendons run.  Maybe you've got some tendonitis.  It's a little hard for me to tell from the pic but when you say "bruising" is there discoloration or just swelling?  If just swelling that points even more, in my opinion, to tendonitis.  If there's discoloration - that would lead me to believe something more like a sprain, but I assume you didn't have any sort of traumatic event, especially since it felt OK right after the race.

Rest and ice seems in order.  If it doesn't improve over a few days I'd probably go to a podiatrist and see what a pro has to say.

Good luck.

Jim

First, congrats on your Half, although it appears you have paid a  steep price in pain. I want to second Jim's comments above on your foot,  but have to ask you about your neck, since it is bothering you enough  to stop you from running.

By "torticollis,"  are you referring to a true "wry neck," or just stiffening of the neck  that prevents normal movement. There can be different causes for the  condition and different "cures" to match, but stiff or twisted necks are  pretty easy to find out there, and often due to postural issues during  work (common), sleep (also common), while sitting watching tv or computer (all too common), or the occasional muscular strain while  reaching or lifting overhead (less common but can produce a nasty case  of it). The rarest forms involve nerve compression or other neurological  and spinal causes that may be simple or difficult to treat. If the  average chiropractic adjustment does not make it disappear (could make  it worse), it is probably more complicated.

A  patient of mine in his mid-eighties, who was a hurdler in college, had  gotten used to his head being tilted to one side. We often see this in  the elderly, and it is often due to accumulated stresses or lifestyle  issues that gradually take their toll. In his case, the unequal stress  of taking hurdles with the leading leg so many years ago had probably  caught up with him. In a few minutes on my table I had straightened his  neck again by working on his chronically tight Sternocleidomastoid muscle, which can easily pull the neck to one side. He was greatly relieved.

I've  had a case of my own lately that might not be true torticollis, but  prevents me from turning my neck from side to side or moving it  rearward. I can solve it in seconds my placing my fingers in the groove  between my collar bone (clavicle) and upper Trapezius muscle, and  probing for tender spots underneath where the Levator Scapula and  Posterior Scalene muscles can be found. Instant range of motion, but I  hurt this area so bad when I was hoisting a 24' ladder overhead, that  the problem returns intermittently. It will eventually go away after the  muscles have fully recovered from the strain.

In  cross section, you can see how much of the mass of your body is  represented by muscle tissue that is rich in sensitive nerve endings. It  doesn't take much for a little pain somewhere in all this meat to  spread throughout the area, even though the pain is often blamed on comparatively  tiny structures like the neck bone (6th cervical) that you see at right  center. This is a recurring theme when symptoms are discussed. People  are curiously slow to notice the 800 pound gorilla in the room. ..

About  your foot, there is a muscle in the region highlighted in your photo,  called the Extensor Digitorum Brevis, that can produce cramps in the  toes and pain in that area because of its sensitivity. Activate the  muscle by extending your toes upwards with your foot flat on the floor  as depicted. If you place a finger on the area in your photo, you can  feel it flex when you do this...

While the pic from Gray's partially obscures the Extensor Digitorum Brevis with the superficial Cruciate Ligament, the muscle begins way back at the heel bone, extending underneath the Peroneal tendon sheaths, on its way to the toes. Because of this, its pain  symptoms range from the toes to the area you describe. Swelling in these  muscles can actually widen the foot so shoes seem tighter than they  really are. Restrictive shoes (based on your photo, I think yours may be  too tight) stifle circulation in these muscles and irritate them. They  also prevent the natural motion of the muscle to lift the toes with  every footstrike. Look for a  longer, wider shoe with a roomier toe box and better flex in the sole  (it should have special "flex grooves" to promote this movement).

Another muscle underneath the EDB that travels from the heel along the base of the foot to the little toe, is called the Abductor Digiti Minimi.  You can activate this muscle by spreading your toes outward, where its  action to "abduct" the little toe to stabilize lateral motion of the  foot comes into play. One important symptom of strain in this muscle is  feelings of ankle sprain that show nothing on x-ray or mri.  The pain pattern even more closely matches your description, even  extending rear to the heel. Pressure from the muscle may cause some of  the discomfort that begs "popping."

Be careful, when massaging these muscles, not  to irritate them further. Avoid wearing elevated shoes or notoriously  unstable shoes like flip flops, although there are probably a number of  well-constructed, supportive exercise sandals that may give them relief.