need help fast! Mastitis with weaning?

I need some fast help and i know you mamas know your stuff . . .

We had decided to do child-led weaning because Dacey and I both were still enjoying bf'ing past her first birthday. So I was so looking forward to nursing her through toddlerhood . . . She is 14 months now. Last week, she came down with a urinary tract infection and in the midst of this has basically started weaning herself. As heartbreaking as this is, I have done everything I can to encourage her continuing, but when I offer the breast, she starts CRYING.

Anyway, in the course of about 3 days, she completely eliminated her daytime nursing sessions, and has only nursed once (at 10:30 pm) in the last 24 hours. She would generally still nurse two or three times a night prior to this. Now my left breast is feeling very tender and I have tenderness in my left armpit, too. . . Could this be the beginning of mastitis?

I have been extremely exhausted because with the UTI, she is up several times a night and since she won't nurse, it takes a long time for her to go back to sleep . .

I obviously have never weaned before, so is some tenderness normal with weaning?

Sorry this is so disjointed . . . I am really, really sleep-deprived.

Thanks for any help/suggestions/encouragement!