Sleep trained, then sickness after sickness, total regression. Wean BF completely?!

I'm desperate (yet again). We night weaned/sleep trained my 13-month old with modified CIO about 6 weeks ago. Took 2 nights of crying, then the first two weeks were great, she *mostly* slept through the night. Then she started daycare and has been back to back to back to back sick (and us too). During sickness, she obviously sleeps badly and I tend to her to make sure she can breathe, isn't too hot, congested, etc etc etc. So long story short over the past month we've slowly but surely regressed to basically waking and nursing every 2-3 hours, and I cannot survive this any longer.

I could "retrain her" with CIO (gentler methods just piss her off) but I can't help but think that with the continuing onslaught of sickness, we will "train", then regress, then "train", and I just want to confuse her and make her have to go through repeated crying it out periods.

Should I just wean BF completely, would that help the problem? I also plan to TTC in a few months so I planned to naturally stop when my supply drops whenever I get pregnant.

She falls asleep easily at bedtime, then wakes up and cries on and off until fed, every 3ish hours overnight. Has always been this way. She self soothes with her thumb but she'll continue to wake and cry on and off until fed. 7-7ish nights.

To wean or not to wean?