Sounds like there are many different issues here that you gather under the "animal" umbrella.
1 - Your partner is the crazy cat lady - or just the crazy animal lady. I don't see a problem with that, I'd be one myself if I could afford it
2 - Cleanliness. I'd be bothered by what you describe the cleanliness of your home is, too. But your partner does not seem to see the problem, and you can't
make her have a problem with it. All you can do is take care of it. If it bothers you that much, deal with it yourself. If it doesn't bother you enough to take care of it, don't complain about it. It may sound harsh, but it's the key to happy cohabitation.
Here's someone who talks more about it.
3 - What you just added - that she equates criticism with lack of love. That sounds like a true problem to me, and with just the information you give us I'd say it's pretty immature on her part. She may feel quite insecure in her relationship, but how is she - how are the 2 of you - going to deal with the communication necessary for real conflict resolution? You may want to read on
nonviolent communication, it's a good way to convey justified criticism in a way that won't hurt the interlocutor. If, after you've worked on that issue, she still answers criticism with "why don't you love me?" that could just be manipulative behaviour on her part, in which case I don't need to tell you what to do.