3 year old having hard time adjusting to transition

[lokismama]

My 3 year old boy turned 3 in mid-January. In the first week of February I found out we had to move and I was very upset for a day due to the circumstances and he saw me crying severely and very stressed. After that I just got very busy and looking for a place to live and he suddenly saw me packing and taking him to see different places and trying to talk excitedly about our new house. I moved 2 weeks later in with a friend with a 2 year old girl. My son was amazingly patient with her, sharing his toys and space in the 2 rooms we are renting, and not hitting back when she hits etc. He has a lot to adjust to as far as a lot of new rules and standards for cleanliness and behavior here, not to mention the confusion of daddy living somewhere else, etc. The other mama seemed to be overly critical of my son, even though i knew he was being amazingly good and was correcting him constantly and more sternly than i do. I noticed he would start to cry and was beginning to get impatient with the little girl and in my fear of the situation not working out, I felt myself getting more stern and impatient with him in the time he most needed me to be my usual self. A few days ago, he hit the little girl on the head with one of his trucks. The mama seemed quite upset and I was harder on him about it than I ever have been about such things in the past and the whole day went from bad to worse- more and more acting out and agressive behavior and more anger and impatience from me. Now the two of them can't be together at all, the little girl starts hitting and my little guy starts throwing and screaming and is now hitting and pushing me and everyone else he comes in contact with and seems very out of control. He also seems very upset about sharing his toys and space which i totally understand but cannot explain to a tiny girl. I feel so regretful that I did not stand by him with more patience and support and gave in to social pressure and stress. I am trying to really be there for him now. I have also had the flu for two weeks, am trying to move from my job and my old place, and am now getting ready for move from this situation to our own place in two weeks. I wish I had some help to get him thru this transition. He can't be out of my sight for a second as I am afraid he will hit and I don't even feel like I can take him to the park right now. We were at the drs office for 1.5 hours today and ended up leaving before being seen because I couldn't keep him away from all the people and the kids in the waiting room and his behavior was terrible. Last night he slapped me so hard on the face that it stung for over 20 min or more and today when he got frustrated with the little girl he hit me and later he was biting and hit me and he hit me again tonight. I feel desperate. I myself am so tired- my mom was going to take him one day for 2 hours and i needed it so bad but she herself got the flu and could not watch him. I feel like I cannot ask any friends to watch him and feel scared to let anyone take him for fear of them being unable to cope with his current behavior. He has also started doing things like trying to run off down the street and repeatedly taking off his car seat belt while I'm driving. He is regressing also into throwing stuff around, being destructive, some baby talk and just saying, "no, no, no" and hitting and throwing which seems very 2 year old-ish and in some ways is copying the little girl. This is coming after such a peaceful good time with him where I thought all the crazy behavior was over with. When he acts like he has this week and other times the last month I wonder if he has ADHD, or something, but it seems like these behaviors come mostly in times of stress. I just wish I knew how to help him- I need the world to be able to accept him and I feel like I can't let him out when he is acting like this- everyone he was around the last couple of days he was pushing or hitting or otherwise acting rudely towards. Need help!!!!