Sorry you're going through a rough time. I know it's hard enough when you've got your own issues and then in addition you're dealing with someone else's as well. I'm currently in a situation like that, and some days it's all I can do to keep myself together.

Do you think your mum may have undiagnosed age-related diabetes. That often results in wounds that appear and don’t heal on feet.
I would recommend an anti-inflammatory diet. Research shows that auto-immune diseases, diabetes and any inflammatory symptoms are managed well long term by dietary changes. The biggest aggravating things are sugar and artificial sweeteners and best are herbs and other veg. I will share the arthritis anti-inflammatory diet with you. [arthritis.org]
Another thing to consider is anti-biotic use can make you feel very run down and can kill off the good bacteria in your gut, causing more inflammation. Consider a good pro-biotic long term for your digestive health- it won’t harm anyway.

Sorry about all that.

I looked online and found numerous articles naming CBD oil and cannabis as treatments for diverticulitis.

Example: "Tetrahydrocannabinol (THC) and cannabidiol accelerated the recovery from cytokine-induced increased permeability; an effect sensitive to CB1 receptor antagonism.

These findings suggest that locally produced endocannabinoids, acting via CB1 receptors play a role in mediating changes in permeability with inflammation, and that phytocannabinoids have therapeutic potential for reversing the disordered intestinal permeability associated with inflammation."

[ncbi.nlm.nih.gov]

Also CBD oil and cannabis treat diabetes, which might be what's wrong with your mom.

Link: CBD compound in cannabis treats diabetes, researchers find [diabetes.co.uk] via @Diabetescouk

Sorry about your current health conditions. Diverticulitis is not fun. I know one who also suffers from that disorder. Hope you find an effective treatment.