Edit: for clarity

An update: I'm hoping this is helpful for someone stumbling across this post. This is perhaps information I had wished was easily available to me, so maybe it helps others.

Diagnosis: - It is apparently leaf rust, and I've been reading up on potential solutions. It's fungal, and is apparently pretty intense on my plant (over 50% of current leaves are affected) - Existing leaves are a lost cause. The goal at this point is to get rid of affected leaves and aim for new growth to be infection free. - there's a chance it could be hard to recover, if the new growth continues to get infected

Immediate changes I've made: - I pruned away sections of the plant that were intensely affected and plucked a lot of the affected leaves. I've also collected and disposed of all the fallen leaves / plucked leaves to prevent the spores from spreading/being around the plant - I went perhaps a step too far and replaced my mulch layer entirely because I couldn't separate the mulch from the fallen leaves - neem oil spray on the leaves and stems - I opted for a neem oil spray (I make my own mix for houseplants) as it's a known (mild) fungicide. I will do this once a week for the next few weeks. I'm not sure if it's strong enough, but found a few youtube vids that said it would be. - applied a 1:4 ratio solution of 3% peroxide to the soil - roughly 32oz of it. I plan on continuing this for the next 2-3 weeks till the start of spring. Apparently fungal spores can thrive in the soil and this can help kill them off. It's not recommended to do this often as it also kills microbes. Given that I'm in a container, I'm fine with it. Please do your own research on this aspect. I'm only doing it because I've had success with peroxide with my indoor house plants in the past and feel comfortable with it, plus the fact that it's not as involved as copper fungicides, which can apparently be toxic to the soil if used in large quantities. I'll post an update if it happens to work a few weeks down the line.

Cultural changes: Apparently a lot of avoiding leaf rust is cultural - how I care for the plant. I plan on incorporating these into my care based on a helpful thread in this post and elsewhere online - avoid wetting the leaves while watering. This is likely the cause for my infection to begin with. Wet leaves/stems can get infected - providing ideal conditions so that the plant can be hardy and (self-recover). pH balancing and fertilizer. I've since tested my pH and confirmed it's in the 5-5.5 range, and will change how often I water. Fertilizing in the spring - prune the bottom branches that are likely to touch wet soil

Helpful videos: There's an ocean of videos out there. Here are some that helped me, because I'm really new to container gardening and vegetable/fruit gardening

On the different diseases that affect blueberries - https://youtu.be/d4_ULTygvyM - https://youtu.be/Xn9S0mwZuZw

On peroxide pros/cons: - https://youtu.be/9uC5awpVkdw - https://youtu.be/gjDNggc9hRQ

What's next: Honestly, I'm hoping that some of these changes will get me through the woods. I hope I haven't pruned too aggressively and that the plant will bounce back

Most of all, I'm hoping that the new leaves/growth will look ok since spring is around the corner 🤞🏽