With Tessa, once she decided she liked me, she started resource guarding me. Dharma could not come near me without Tessa getting in her face, barking and growling. Fortunately that did not take long to really get under control. Also she ended up having pretty bad separation anxiety. She does fine as long as I leave her here with Dharma but if Dharma and I leave, well, lets say it's not pretty. The first time I did, I crated Tessa but I came home, she had managed to tear the entire front of the crate off (not the door but the whole front panel) and in her panic destroyed my fireplace screen, broke down the baby gate to get upstairs then broke down the one to get in the spare room and destroyed both sets of blinds in the windows.
I have never fully gotten her over the SA. She is never left totally alone anymore. If Dharma and I both are going to be gone, my uncle comes over and stays with her. She can pretty much get out of the crate if she really wants to. The last time, despite the fact I put zip ties all around the panels, she got the top bolt undone and squeezed her 90lb+ body out a 6in opening. That was after jumping around so much she turned the crate around 90 degrees. She is quite the Houdini.
I have also had some aggression issues where she will bully, growl and bark at Dharma. It is definitely worse if she isn't feeling well. So I make sure she goes to the vet at the first sign of anything wrong and make sure she gets her Previcoxx and glucosamine daily for her hips.
She is also food aggressive, so she has been fed in her crate from day 1. ALL treats were given in her crate for months. In fact to this day if she wants a treat, she will go sit in her crate and bark at me. The last month or so she has gotten better and can have treats out with Dharma now.
I also had an issue where at night when it was time to go to bed, she wouldn't let Dharma come up the stairs. It seemed like it took forever, I would have to stand at the foot of the stairs with her, blocking her so Dharma could go up the stairs first. Of course then Dharma would be wary and not want to go. There were nights I wondered if I would EVER get to bed. That has improved dramatically in the last few weeks. She just follows me up the stairs now and doesn't worry about Dharma.
Honestly, there were times when I was afraid I was in WAY over my head. But I also knew she had NO where else to go and I was her last hope. Even with VGSR behind me, she would be difficult to find another foster for. So I just kept persevering and never gave up. We still have our moments but for the most part things are good. She is worth it though.