I'm basically a coward when it comes to becoming shark bait
I'm with you on the sharks, Sam. Saltwater pools are the items to have in your neighbourhood.
Spoke with our son last night, and showed him your post. His observations:
1) The kind of injury you describe sounds like repetitive strain injury. These usually result from prolonged heavy usage, and sometimes from heavy usage done without buildup training. David was surprised to hear that it might have some from cycling uphill.
2) He thought it would be useful to continue with the anti-inflammatory tabs and the roller, acknowledging that the latter can really hurt. He said you might try using a cricket ball, rolling that up & down over the area -- that localizes the pressure more than the big roller. ("Oh joy," I hear you saying -- "more tough love.")
3) If you don't feel any improvement, get specialist advice. (I'd add--easy for me to say--how quickly could you see a sports-injury specialist, maybe with a view to getting an MRI?)
4) After repetitive strain injury to the ankle and/or calf, the usual treatment for rebuilding/strengthening muscles is called "eccentric loading": Stand on a stair step or a 2 x 6 on a level surface with your heels protruding over the edge. Lift one foot, putting your weight on the other. Raise yourself on the ball of your foot, then ease back down, past horizontal, then raise your foot to horizontal again. Repeat with the other foot. (Your physio or other specialist would give you more specific directions.)
Good luck with this, Sam. Look forward to your stories of (more-or-less? -- we are getting older...) painfree cycling soon.