2 year old driving me nuts!?

My son is 27 months and is starting to really make me miserable. He cries and complains constantly about everything. Whenever we have to leave somewhere that he wants to be, I have to pick him up, and then he hits me. He does not play with toys, he just throws them around. Even when he is not crying, he talks in the whiniest voice. He screams when he has to ride in a shopping cart, but my husband is never home, so I always have to take him shopping when I go. This has made me hate shopping so much. I feel like everyone is staring at me and judging me. We can't go out to eat because he will not stay seated and he refuses to sit in a high chair. He very rarely seems happy, and this is in sharp contrast to how my six year old daughter was when she was two. She was so well behaved, never complained, and rarely cried. My son goes in timeout, but I don't know what else to do. I just want to scream. I am with him 24/7, and I have a feeling he will be giving up naps soon, as they have been getting shorter and shorter. I feel like my husband has no appreciation for all I do, even though he gets super stressed himself on the rare occasions that he has to take care of our son. I have no friends that have children, and I don't have anyone to talk to about this. I'm afraid people will think I'm a bad mother for feeling this was, but they have no idea what I go through day in and day out. I used to be a morning person, but now I feel sad in the morning, knowing what is in store for the rest of the day.