Wheel buckling 2 weeks before first trip. Help!

I've got my first bikepacking trip coming up in two weeks and disaster has struck: my rear wheel spokes keep breaking. It's not able to carry the weight of me (I'm 230 lbs / 104 kg) and my gear (maybe 15 kg).

My bike bike is a Boardman ADV 8.9 XL gravel bike fitted with standard wheels:

https://www.halfords.com/bikes/adventure-bikes/boardman-adv-8.9-mens-adventure-bike-2021-orange—s-m-l-xl-frames-431854.html?_gl=1*shjjnf*_up*MQ..&gclid=CjwKCAjwodC2BhAHEiwAE67hJH4AAe9H4dKsIEhhcr0O2G898NstVes4I9vUWZXlcujwf9hDNEyRfhoC35oQAvD_BwE&gclsrc=aw.ds

I'm looking for advice on getting a good replacement wheelset. It needs to be off the rack because I'm leaving in two weeks.

I've been looking at the DT Swiss Spline 1800s but the weight limit seems tight.

I'd prefer to spend less than £200 but can go over if necessary. I also live in a fairly rural area so don't have great access to bike shops.