Pls help - need solution for obsessive nursing & all night pacifying

I'm really hoping someone can help me with this. I'm 9 weeks pregnant and my 18 month old DD is still BF'ing. I was hoping to BF her through this pregnancy & then tandem nurse. She's always been a frequent nurser and has just recently started eating more solids. For some reason for the last 4-5 weeks she's become obsessive with nursing. She nurses 2-3 times/hour. Sometimes she's on for a few minutes, sometimes it's 15 minutes. If I tell her that "nummies went bye bye" or something along those lines, she pitches a horrific screaming fit. Yesterday I nursed her, then drove 10 minutes to a store to run an errand, and the minute we got in the store she screamed "NUMMIES" at the top of her lungs until I nursed her. My BBs are getting so sore.

The other problem is she's also become an all night pacifier. We co-sleep so I rock her down to sleep, hold her in my lap in a recliner, go upstairs about an hour later and then anywhere from that moment to a few hours later she starts pacifying. She says, "Num, num, please mommy, num" and if I don't let her nurse she fully wakes up and cries and screams and is almost impossible to get back down. She'll pacify 2 times every 30-60 minutes ALL night long. I'm getting no sleep at all and I'm exhausted.

I really want to keep nursing her but I can't keep up at this pace. Does anyone have any ideas re what I can do? Also, why would she be doing this now? I thought that when women got pregnant the nursing usually decreased somewhat. She is getting some new molars, but this has been going on for 4-5 weeks. I'm to the point now that I dread going to bed and I am stressed about spending our days together. I know that's an awful thing to say and I feel so guilty for feeling this way. Does anyone have any advice? TIA!