Is it too late to teach 15month old to self soothe?

[Minions]

My 15m DD has never been a great sleeper but not terrible either. Around 11months we had some success putting her down awake and letting her fall asleep in her cot but with one of us in the room. Then she wasn't well, then I went back to work and her routine changed and then not well again. So, she got used to falling asleep again on us as I felt she needed the comfort.

Now when I try to put her in her cot awake she howls and is so upset. I know controlled crying works for many but it really isn't for me. She needs me touching her, even just lightly, to fall asleep and is waking up 3-6 times a night. Most of the time she needs picked up and cuddles to get back to sleep. DH and I are just so tired. DD catches up on sleep in her 1.5-2hour nap in the morning.

Is it too late to teach her to self soothe? I know I probably have a baby that won't sleep through but even if she woke just once or twice a night it would help. Apparently I woke through the night until I was 10 years old. Help!