Hey Exile, welcome to the group
You're in good company with other members who understand the emotional roller coaster: the good times are really good, and the bad times are really bad. Everything you're describing -- the wildly varying, harmfully intense emotions; the anger/rages; the threats; the dysregulations -- is pretty common to hear about, so you're not alone here.
You mention you have a daughter together with her, and she has a stepson. What other kids do you have? What are all their ages? Also, when did your grown stepson move back in?
Do you still have the contact info for the male counselor you'd seen? What happened to make it seem like you couldn't talk to him again?
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I know you have a lot of questions; it sounds like you're willing to try to improve the dynamic between you two. While it can be uncomfortable, it is possible to impact the dynamic when we work on and change ourselves. Our workshops on
Relationship Skills are a great place to start.
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Would you say the bed/couch conflict is the biggest conflict between you two right now? Or something else?