mummy guilt

So I am 27 weeks pregnant with my second baby and our wonderful little girl is 17months. but currently am really struggling. I had a year off with my first exclusively breast Fed and even though I am back at work was still feeding at least twice a day but now she seem to want it all the time. I work full time as a hospice doctor a job I absolutely love but it is tiring especially as we are really busy. the last week or so I have just been exhausted meaning I have really struggled to give my little girl all the love and attention I would love too. she has never ever been clingy to me (which has always made me doubt myself) and now she suddenly much prefers her dad and often pushes me away only wanting pappa. I am not jealous as I absolutely love their relationship. just worry that I don't love her enough or don't shoe her enough and by the end of my pregnancy being this tired she is just not going to know how much I care. I don't know what to do should I work less and spend more time with her. Is this just a phase where daddy is more important and at some point she will want me more again. should I stop feeding her as mommy milk is all she seem to want me for would she then want me more? any advice appreciated. maybe I am just being silly and emotional.