Doesn’t feel like a marriage

Hi everyone, I am just posting to get some different point of views. I want to know if I’m wrong for this.. but I have been asking my husband for a key to the mailbox. We get our mail sent to his cousins house, so he went out and bought a secure mail box with a lock on it but didn’t give me a key. So only him and his girl cousin have a key. I’ve already asked him several times for the key.. then today we went over to his cousins house and he was getting the mail. I told his cousin to make me a copy of the key and that I would pay her for it. Then my husband says, “ you can’t make a copy from these keys”, I said, “what!? Yes you can”. He’s like idk why but u can’t from these. Then his cousin said that they have a contract together and won’t make a copy because the mail will get lost and then other people will go into the mail box. So I told my husband he was crazy! I got so mad and told him he was dumb! I’m sorry, but at this point I’m so fed up with his shit. I don’t feel like I’m even his wife. He treats me like I’m a damn child or someone insignificant that he can’t trust me with a damn key to get my own fucken mail. And this goes beyond the key. He treats me like I’m just shit. Ignores me all damn day, doesn’t come home until late at night and yet wants me to do all my wife duties including sex when he wants it. I am so tired of his selfish ways. Just the other day I asked my neighbor, “his sister in law” to watch my daughter because I had to go to an orientation at my college. When I got back, I went over to get my daughter and knocked then opened the door and his sister in law says, “ay you scared me”. I asked her why did she get scared that I just came to get my baby. And my husband was siting at the table eating and she was right next to him standing up. I’m sorry, call me crazy but why would u get scared? Like wtf are you guys doing? My husband flirts with everyone!!!! And he checks out every girl that crosses his path. He seriously makes me sick to my stomach, and makes me sick physically and mentally.. I feel like I just can’t trust this man and I always feel sick because I am always worried and stressed wondering what he’s doing, why he’s never home and why he lies about going to work when he’s not even working some days. I have confronted him about having another girl or girls and he just denies it of course. But he seriously never wants to spend time with me. And his excuse is because we’re always arguing and I honestly don’t think that’s a good enough excuse. We argue because he always ignores me and goes over to his neighbors house first, before coming home to me. He confides in other women and spends more time with other women more than he does with me. Call me crazy or jealous, whatever u want.. but I don’t see how it’s right for a married man or a man in a relationship to always be at a females house alone, without her husband even being there. I would never go over a guys house without their partner being there or my husband there. Can I just please get some serious advice here?