WIBTAH if I stopped volunteering even tho they need my help?

I’m sorry this came out kinda rambly and long. So some context I (23f) have been volunteering at a cat shelter every Friday for around 5 years now. When I started 5 years ago there was a completely different set of people that volunteered. They quit for a plethora of reasons but I’ll just say no one lasts very long. There are only 3 other volunteers that have been there as long as I have on Fridays (this will be important later). They treat it like a job rather than something people do with their own free time to be nice. They have always been a little passive aggressive if I ever say “I can’t come this week”. Which leads me to overextend myself or miss out on things if they’re on a Friday.

I’m a senior in college now and it’s my last semester. I met someone who I’m serious about and he lives in a different city that’s an hour away. He works full time so we only get the weekend together. I have a job lined up in the city my bf lives in and I took the job because they said they would work with me so I can still go to the shelter and I told the other volunteers this, they were very happy I was still going to volunteer.

I started going to the shelter 12:30-4 and cleaning 1/3 of the shelter by myself before everyone gets there at 3, so I can leave at 4 and be with my boyfriend by 5. If I don’t go in early the rest of the volunteers get out late and aren’t able to do more basic care like cutting nails and brushing the cats. I feel like I made myself too useful in a way and it’s now expected of me to go early and clean by myself.

So circling back around to the original 3 volunteers, I am going to be changing their names. They’re all retired women who volunteer in their free time. They all go multiple days a week. Rose is kinda like the “acting manager” she has vet experience so she does all of the meds and people look up to her. There’s Emily who has severe undiagnosed OCD that she refuses to treat (she knows she has it and does nothing about it). This leads to her having to have things done in a specific way and she spends probably double the time doing things that everyone else does, she is also harsh when giving criticism. However she cares deeply for the cats and is nice besides that. Lastly there’s Brenda who would do a different 1/3 of the shelter, foster cats, take them to and from clinic, and communicate with volunteers if they couldn’t make it that week or recruit new ones. Well Brenda and Rose got into a fight a few weeks ago and last week Brenda announced that she will no longer be coming but she wishes us the best.

I have a feeling that I’m going to be asked to do more than I already do. Would I be the asshole if I stopped going? I feel really guilty because I love the cats it’s just the politics of the shelter that I hate.

TLDR: would I be the asshole if I stopped volunteering at a shelter bc I’ll be asked to do more since someone quit?