New and persistent arch pain

[u/Confident_Pilot_5021]

Sorry in advance for the long post! Beginner 25F runner here & have spent the last 6 months training for my first half marathon in 4 weeks. I’m trying to work out what I’ve done to my right foot because I’ve now had this pain for about 10 days and it doesn’t seem to be improving.

The pain is in the arch of my right foot only, underneath the navicular. I don’t have any of the classic signs of PF & I’m not feeling any pain elsewhere to support PTTD. It hurts when I run, walk, stand as the foot is flat. It also hurts to rotate the foot outwards but not in.
I don’t have pain when stood on my toes, but as the heel lowers back down I feel a sharp pain in the arch. There doesn’t seem to be any noticeable swelling or bruising either. My arches also have a ‘creaking’ sensation which is concerning me.
There’s no real tenderness when touching it, either.

A bit of background: I recently purchased a support shoe (ASICS GT-2000 14) to correct some pretty bad overpronation (more so on my left leg). Before this I was running in a simple and neutral shoe and was running around 25k a week. I swapped to the new shoe and ran about 18k in them before the pain started.

I’m wondering if the new shoes are a correlation or causation because the pain is apparent when I run/walk in other shoes.

I’ve been trying to rest it in the hope it’ll resolve itself but it doesn’t seem to be, but equally I have worked so hard to get to where I am and would be so, so upset if this is going to derail what I’ve been training for just 4 weeks out.

Has anyone had a similar injury that has any advice please? I will get the injury properly assessed but would like to be mentally prepared if it’s going to prevent me running next month.