Don't worry too much, my DS is 1 year old and feeds to sleep quite a lot, he can settle himself if he wakes up in the night though and will go to sleep ok for his Dad for example. I work shifts so am not always there to get him to sleep but I get a wee cuddle when I am
I have never trained him to self settle so he seems to have just got the idea himself over time.
Also your HV is talking crap, your daughter is getting lots of nutrition from your milk so can have as much as she wants/needs. I think HVs panic about how much they feed vs how much solid food they eat. Even at my bf group the other day one was talking about discouraging people from feeding older babies/toddlers too much. 
I like to think of it as weaning on to food rather than off of milk if you see what I mean.
DS was feeding about the same amount at that age, he is now feeding morning and night and occasionally an extra one during the day if he is struggling to get to sleep for a nap for example. (or at night if he is poorly for example - I have always fed him at night if I needed to but he sometimes just needs a cuddle, so I don't think he is dependant on it to get back to sleep)
There are techniques I think to gently break the feeding to sleep habit I think if you need to, hopefully someone knowledgeable will be along to help with that.
Hope you get on ok going back to work, I have been back since DS was just under 6 months and the time has flown past!