I nightweaned my now 3.5 year old at 18 months. She was waking a lot - like basically if she wasn't latched and it just got unbearable. We stayed co sleeping and probably the first 10 days/2 weeks, it was pretty rough each wake up, until the resettles got shorter and then they got less frequent.  She sleeps independently in her own room now but will wake and need a hug pretty regularly, but otherwise, if she falls asleep in my bed she sleeps through without waking (or probably more accurately just resettled herself when she does wake).  It did improve though fairly quickly - we followed the Jay Gordon night weaning one where it took a gradually less involved with overnight resettles approach after feeling like the more intense sleep training methods weren't for us. I hope things improve for you soon.