My son is 19 months old but still need a breastfeed to soothe him before go to sleep. What are good ways to help him sleep without breastfeeding? And by the way, how bad this could be if I let him continue this habit?
Our daughter continued breast feeding until she was over 2. The way we stopped was to provide her with warm milk as a substitute and simply to say that "Mamma's milk has stopped." She was old enough to understand what this meant, and accepted it.
In don't think it is a bad habit. Plenty of studies show the benefits of breast milk (so long as you are willing and able to produce it).
Create a consistent bedtime routine that will help them fall asleep. Elements of a bedtime routine might include bathing (if it calms them), changing into jammies, bedtime snack, reading stories together, listening to music (preferably calm age appropriate music at a quiet volume), turning a fan or white noise on, turning the lights down or off, being tucked into bed, holding a favorite stuffed animal, hugs and kisses, etc. Some kids adapt well to here's the new routine and just being consistent with it is enough.
Or if you'd prefer a more gradual transition, first work on not falling asleep still nursing. Once she is past the point of drinking to quench hunger or thirst and is just comfort sucking, and is "drowsy but awake", unlatch her, and continue to hold her and rock her to sleep, or lay with her while she falls asleep. After she gets comfortable with that, try rearranging the routine--we'll have our milk first and then stories and then lay down and go to sleep. Later you can decrease the time to nurse for--after five (and then three and then one) minutes if you're still hungry you can have a bottle of warm cow's milk to drink. You may wish to introduce brushing teeth as a bedtime routine element between the milk and stories or being tucked in as well. Eventually, talk up how instead of having mommy's milk we are just going to have the other milk at bedtime.
But it's not bad at all should you decide you are comfortable with your current routine and wish to continue nursing. Keep at it as long as it is mutually agreeable. (eg: if you got pregnant and it was painful to nurse, or your milk dries up, you might be less agreeable to the current routine). Eventually, the kid will outgrow wanting to nurse at all. Anecdotally, those I know who have chosen to do a child-led weaning typically found sometime between 3-5 years old their child chose to wean on their own, though occasionally younger.