Work Frustration

So I haven't written anything in a long time. This obviously is not a poem, I'm not sure on how to put things under titles and stuff but anyways I am really frustrated with work. In the almost five years I have worked for Family Dollar, I have not had such problems as I do now. My store most of the time looks like crap, I do not close but like once a week and I do a good recovery on those nights, but it seems like I am the only one doing it!! They let Jon go and brought in someon else which she does not know what the hell she is doing. I have had to teach her on how to do the cycle counts and ordering and the damaged and stolen products and how to put them in the computer and how to send emails and various things on the computer. For the first few weeks I was the one doing all of it. Then I will tell her something and she will look at me like I don't know what the hell I am talking about and she will call her daughter of the Salt Lake store and her daughter will tell her the same thing as I did and then she will do it. She makes me feel like I'm an idiot. Now we have two of hour employees fighting with eachother and one says it's the other that goes or they will. I'm getting way overwhelmed. I stress enough about my store, I do my best but I am getting so worn out. There are other things that I could add to the list that bug me and that are stressing me out but Will leave it at that... Everyone used to ask why I don't go find a better job. I didn't think I needed to, but with all this happening, it makes me think maybe I should. I don't know. If I am taking on all this, I just don't see why they didn't give me the store that has been like my home for all the years I have been there.