@PotomacBob
I also have a WIP, with 1 POV, and I find that very limiting.
Limiting is the point.
This won't help with your writing issues, but as to your mind-set going into writing I would suggest:
1. Multiple POV is for when you want to tell a story.
2. Single POV is for when you want to explore character development.
Obviously there's a lot more to this conversation than that, and either writing style can be used for either type of story, but this should help you to focus on what you want to achieve.
The purpose of using a single POV of to focus on that one character's experience. You're not explaining the broader scope of the story. There is no ultimate truth or falsehood. Mistakes will be made and that's the point. You're focusing on what this one character is experiencing and how they react to it.
While limiting to write, these kinds of stories can often be the most fun to read.
If you have two POV characters, how to you handle it when the two characters interact with each other?
The same way you handle multiple characters in a single POV story. Unless you are doing something very strange with your POV -- which I highly discourage for anyone who doesn't have a professional editor -- each character is the only POV character to themselves.
If you're in Adam's chapter and everything is Adam's POV, then Brian isn't a POV character, Adam is. Brian's thoughts, emotions, and knowledge are only important to the extent that they are communicated to Adam and Adam cares to listen to them. In Adam's chapter, alternate-POV character Brian is no different than non-POV character David. They are both third parties.
If the conversation is vitally important to both characters, then when you later get to a Brian chapter you can reference it. I wouldn't retell it; most audiences get bored by repetition. The fancy way of handling it is to have Brian act in a way that shows that their understanding of the conversation is different than Adam's, but if that's not feasible a short flashback or reference to Brian thinking about the conversation will work.