What's up with my coworkers?

Hello everybody, this is my first post, so please be gentle on me if I'm posting in a wrong category
I've been now frustrated with my coworkers for some time and I came across this forum so I want to give it a shot.
Most recently one of my coworkers stopped talking to me. She says good morning but that's where it ends. I guess it started after I tried to help her fix the computer problem and she was giving me an attitude so I asked her to stop and suggested she should read more about the topic instead of clicking without even reading what is asking her. Then I went on 4 weeks vacation, but when I got back it seemed to get worse. On the first day back to work, she said hi and welcome back. But before she got to her desk, she spent at least 10-15 mins talking to everybody else how their weekend was. I brought some sweets back from my trip that she didn't even bother saying thank you. So after about 3 hours i asked her how she liked them and she only rolled her eyes and then after lunch she e-mailed me, yes she e-mailed (she sits about 6m away from my desk) to thank me and wrote that she was too busy to say thank you. HUH? Anyway, she is a very messy person and she has her work stuff on a piece of equipment I need to use from time to time to do my job. Each time I want to use it, I have to either ask her to clean it or do it myself. Ive been asking her for years to keep it clean so I don't have to go through that and I just asked her nicely again. I think she should have been less mad at me if I murdered her friend instead. She snapped at me when I tried to offer a compromise that she is busy and don't want to deal with it. But she hasn't dealt with it for years, so not sure when the right time would be for her. It's very frustrating but I don't want to change my job, cause I like it. Bosses are great and I like what I do. Plus there is a big chance at my next job there may be a different person just as coo-coo as she is. Any idea how to approach person like that???
Thank you!