kiwi
DS5 was the same. about same age.
throw all the dummies out and I mean all of them, after you cut off the teat bits. (which means no going back, no option of bin rummaging and mad sterilising at 2am)
then follow Tracy Hogg's "pick up/put down" & "shhhh/pat" methods. or whatever you think is best - but this suited us.
beware it can take up to a week for baby to settle this way and the a very first few nights can be tough so best to start on a Friday night which means you can nap during the day if needed and your DP/DH can take over a bit more. or other way round.
basically when trying to settle baby you put her in the cot. as soon as she cries you pick her up, and rhythmically pat her back while doing "sshhhh" sound at the same time.
(I do it so the shhh sounds like a "wave", slightly louder at the time I pat on the back - IYSWIM)
when she calmed down you put her back in the cot.
as soon as she cries you pick her up again and shh/pat till she is calm. back in the cot...
eventually she will start getting tired - then switch to gently stroking her back, still dooing sshhh- sshhh- sshhh.
when she's quiet the drop the sound and just rest your hand on her back. as soon as you think she is asleep you can leave or go back to bed.
it seems a bit weird to "give in to the crying and picking up", but it isn't what it seems. a crying baby ALWAYS needs attention, needs to be soothed and held. they need to learn you will jump. this is what eventually builds trust and work in your favour - because they don't need to cry for ages to get "help" funnily enough most of them will learn to only cry if there's a problem.
when we did this with DS5, the very first night he woke up 6 times, the second night once, then slept through.
yours might be even quicker or might take longer.
it helps if you document how many times they wake, how long they are up and count how many times you had to pick baby up.
you will see the progress.
if the crying is grating on your nerves use earplugs to muffle the sound (I did)
The most important aspect is to only put baby in the cot when they are not crying. as soon as they do, even if it's mid-air, you should pick them up.
they will eventually learn to self soothe, but first they need sleep training.
but inly if YOU are ready too. no point wasting 2 nights then giving up. start only if you mean to go on.
good luck