I think it’s important not to panic and over worry at this stage. The fact you were able to run your first half marathon a few weeks back is brilliant and we need to remember that. It might even be a reaction from that race. I’m experiencing similar issues in that my legs hadn’t properly recovered from my marathon and I did too much last week and I’m pretty bad shape right now. But that’s fine, I’ll take a week if I need that. Whilst it’s nice to be running well, the most important time to be at our peak is when the big races roll around and the next time that happens is March/April. So even if you need to take a little break or ease off the training for a few weeks it’s only going to be a small step back and it’s probably the best time for it to happen. That’s what I’m telling myself as well. Really hope it’s start to feel better soon Dan. Take the time you need to let it heal. The plan is always adjustable.