Adjust issues with 5yr old - School/Daycare

I could use some seriousl adivce. We have a 5yr old son who we've had since an infant through domestic adoption. He's funny, smart, energetic, and just an all around boy! I've always worked full-time, so my son was in an at home daycare. We've never had any real issues other than he is a complete creature of habit and routine! He loves being home, loves going to his grandma & grandpas farm (we live in the country too). We brought home our new son in March 2008 from Guatemala at 20 months old. Rylan turned 2yrs old in July and it was a 20 month process. Both kids did great at first. It was crazy in our house, but good. Well, about 2 months ago Cameron started doing more pushing, hitting and such. He was having issues at daycare also in that he was bothering the younger kids. There were no boys there his age to play with. Just his brother who was 2yrs old, and others in that age group. Then a 5yr old girl, and older girls. I switched Cameron to a preschool in the area to give him a break. This seemed to go well until he demanded to be picked up at rest time. He hated rest time! At his old daycare, they just rested with a movie. This preschool, it was a lights out nap. It go so bad with me taking him he was screaming, hitting, hanging on to his car seat. I thought "this just isn't worth it for 2-3 weeks". I made a deal with him that he'd go in the mornings. I'd pick him up at rest time, and take him to the old daycare for the afternoon. Deal. He loved that. Well, just after Labor Day Cameron started Kindergarden. We didn't have help in the mornings getting him to school because the one daycare in our town was full. Cameron gets motion sickness so I couldn't take him to anyone who lives too far from school. Our neighbors in the meantime offered to help after I spent the 1st week taking him to school. He did good at first, then about 1 week into it he refused to go saying he got sick and wanted me to take him. He did the same thing there that he did at the preschool. TANTRUM. I felt like I couldn't make the neighbors deal with that!!! Low and behold after LOADS of worries about how I was going to do this, the daycare 1 mile from school had an opening! He's been going now for a week. So what happens this morning? TANTRUM. He said he didn't want to go to school and he didn't want to go to this daycare. He went on and on. This time I explained to him (or tried too) that this was how it was going to be. I pulled up at the daycare, carried my 55lb child in, set him down.... and he ran out. Daycare mom followed me seeing what was going on and got him back out of the car. She held him while I drive away.... I cried all the way to work! I called the daycare after I knew the kids got on the bus and she said she just held Cameron quiety for awhile until he settled down. She took him inside and away from the other kids to talk. She was gentle yet firm in her words. She praised me for doing this. I feel so awful. Believe me, if I could quit my job I would. But I have a very good job, with excellent benefits. I have to be here at 7am. So Cameron goes to daycare from 6:30am until he gets on the bus there at 7:45. I'm there to pick him up at 3:45. My younger son can't get into daycare there yet because they are full, but if he went too, I think that would help Cameron feel more comfortable. URGGGGGG.... I'm sorry this is so long. I just wanted to give some history. I just feel lousy. Like I'm failing my child.