No expert here at all but very happy to share if it helps at all, Pops was flipping hard work until she was about fifteen months old. Recently we're having a whole bunch of lovely days and when we have a less good one (like yesterday) it reminds me how much she's matured. I took some great advice here about diet from members who found their dogs were very different depending on dried food and even different flavours of the same food. We tried a few foods and finally I took her off ALL dried foods and she just eats wet with raw top up. No idea what does it, but if she's had something with grain in it I can really see the difference in what I now think of as hyper/silly moods but which worried me a lot when she was a puppy that it was aggression or reactivity and made her just unmanagable. She is a reactive dog but it's much, much more manageable now.
I also (again on advice here) kept searching until I found things she really wanted to chew (half antler horns, hooves, fish for dogs sticks and cardboard work for her) and when she's loopy the first thing I tried was keeping her busy. A smear of pate deep inside a plastic bottle so she has to chase it, or she loves a treat wrapped in paper inside a box which is inside a box stuffed with toys, that'll take her fifteen minutes to unpack and she loves shredding up cardboard boxes. Things to think about seem to calm her down and direct the energy somewhere useful.
She will now sleep in a crate for a couple of hours while I'm out without the faintest problem (I often catch her just waking up if I sneak in quietly) but at nine months she was still barking her head off if she was crated or even if I left the room and went out of her sight. Some of what helped was making leaving the house a very predictable routine (even same tv channel put on) plus a really good kong, and crating her when I was in the house sometimes even if I was in the room with her. Some of what helped I think was just getting older, she got experienced in how it worked and she grew out of it, I never found anything that worked in coping with me going out of her sight at home other than just keeping on doing it and weathering it until it started to fade. We saw a Behaviourist who did some TTouch with her and that helped get through that time, and I found the book Fired up, Frantic and Freaked Out by Laura VanArendonk Baugh helpful too.
It was like trying to put a collar on a crocodile with springs until about a month ago. She is now getting much better at sitting still and stopping wriggling and bouncing and biting whenever I try to put a collar or harness on. I worked on making it clear nothing happened until she let me do it calmly, if need be we've been by the door coats on and every time she started I just straightened up and ignored until she settled (repeat about 30 times
) but in the last few weeks she's just started to the point of responding to a verbal command to stop and sit still, and she's much easier to distract by singing or talking to her while I do something. Holding her attention used to be a nightmare if she was at all excited. Practicing lots and lots of sits outside by exciting things helped, just getting the idea that she can see something so exciting and just stay sitting and watching, but its taken months of practice and her maturing to get from minutes and minutes of persistence to get one sit, to now being able to mostly get a sit on request unless it's Really Exciting.
And I was over walking her to try and chill her out a bit. Being tired, wanting a poo, being bored, were all things that made her really out of her tree loopy (I'm sure I remember using the phrase squirrel on crack to describe her) and still make her a bit loopy now. A shorter walk followed by a problem solving toy and lots of chewing seemed to help more, and crating with a treat or chew when I needed a time out as well as when she did helped keep me sane. It was HARD, she had me in tears a few times, I have every sympathy with how you're feeling.
