Is this Separation Anxiety? How can I help him?

HandsomeStanley

Over the past couple of weeks, Stanley has started to act strangely. for instance:

1. When I put him in the back yard to potty, he flips out and starts to cry and howl and jump on the back door. He's always out with his brother, so it's not like he's by himself and it's not like he's out there forever. Maybe 15-30 minutes at a time.
2. On Saturday we took him and his brother to the lake. They have a leash law where we were at so we put them on a 25 foot lead. I went with my boyfriend to take a ride on the boat and left them with family (4 adults and 4 kids) and he flipped out again. Crying and howling and jumping like 3-4 feet in the air until he broke his new $40 leather collar.
3. He normally will go in his crate just fine, but lately he acts up and cries and howls when he's in there and knows I'm around.
4. I just moved into an apartment and haven' had a chance to move his crate yet so he's been staying with my boyfriend and his brother. Well this morning my boyfriend said he was moping around the house, wouldn't eat, and just looked very sad.

Stanley just turned 1 in March and when he acts up, I do my best not to react but sometimes his behavior is so bad I don't have a choice. And now I'm even more concerned because I've moved and he will be separated from his brother. They spend every moment together. They will still see each other alot but I don't know what to expect if he's already flipping out and I'm about to separate him from his brother.

I've read several of the threads on separation anxiety but none of them seem to cover this specific type of behavior.

Is there something I can do to help him with this transition and control his behavioral issues when I leave? Now that it's just the 2 of us again, I plan on getting up earlier and walking him for an hour in the morning before I leave for work, I was just wondering if there was anything else I could do.

Thanks!