She refuses to be happy without nursing! 15 months old and I'm 11 weeks pregnant?

I am feeling more and more terrible by the hour and I know I have to stop feeding, but I'm having a difficult time not caving in. I tried for the first time today to begin weaning her and when she asked for it, I offered her both sippy and bottle. She refused both. Then she cried a lot and I held her and snuggled her and we watched part of a movie together but then she wanted it again and I didn't let her and she cried some more. So after the 2 hours, I caved in and she was so happy when she finally got it and was waving at me all smiley and happy and nursed for about 5 mins than ran off and started playin. I just dont think I have what it takes to wean her. But every part of my body is wearing down. Her daddy is the only one that can put her to sleep, but he works nights and can't. He should have a full week off this week and we were going to try then. I've lost 10 lbs so far in this pregnancy and I'm worried about the baby I'm growing. I know both of them will steal nutrition from me, but as it is I can't eat a balanced diet or hardly any diet at that. I do good to eat one time a day. My husband always is on me about eating and drinking because he knows I'm doing worse and worse and I am basically no good to anyone. Any tips advice or anything?