YANBU it can be very hard. I found it odd being at home with my first baby, my days were long but the naps were never long enough to achieve much. I had to be up early, but it felt like hours until the rest of the world was ready for us. I hated 3pm to when my dp came home, hell it dragged by. For me it was one very long day.
I loved being with him but it was hard filling my days. I tried various groups, kept going but never really fitted in. Probably most of the other parents felt that way ;) It is tricky, all these different people in one place, babies are what you have in common, so that's the focus. Same as work I suppose, but the talk is mainly work.
Every situation is different. I was already in a good job, my maternity leave was 6 months back then (good benefits to return with company) so I think that kept me going, mentally I had those 6 months as "our time". Then I went back part time. At 18 months I became a SAHP. I found it easier with my second, there was an established routine to fit into. After the morning rush to get eldest to pre-school I was happy to come back and chill :) I say chill, flop is a better word, before heading out again. That late afternoon period was always a drag. But it is at work too ;)
YANBU and very far from being a bad mother. You have lots to be proud of, you're at uni, you have a daughter, you will get there. How you feel is not wrong.
Are there any uni resources you can take advantage of whilst on maternity leave? It's not an area I know anything about. Child care is expensive but can you get reduction as a student, gym, EDCL (someone else suggested that, or similar).
Whether you're having a moan (all entitled) or would like the short term to change, good luck :)