Writing plays - thoughts?

I have been working on a play project and am therefore writing a lot of dialogue. It so happens that I love writing dialogue. I can start somewhere random and make my characters talk to each other for (p)ages.  The conversations flow. I learn more about my characters by letting them ramble on and argue with each other. I always have a rough idea of their personality when I start, but it's really the dialogue that guides me for further nuance.
 But then I read what I produced, and I think: 'Damnit, I did it again. The plot is gone, if there ever was a plot idea in the first place'.I suck at plotting, and I suck at introducing plot elements in dialogue. So, as my current play project stands, I have chunks, scenes that work as seperate entities but that are only loosely and superficially tied together. Can I move some scenes around? Are these scenes all actually related? Or are there really two plays in this project, each one fighting for the spotlight?

I don't think I could ever figure out a complete plot before starting, and stick to it. I did try this time. I had my three act structure figured out, with the various stages of plot and character evolution. And I must say that creating the outline was very helpful, and still is. I have something to fall back on, and I have an exit - the end of the third act. That's the end, baby. So that means I can't stop now, however tempting that might be (I have a wobbly first act, and two scenes in Act II). But, the outline only works - kind of - for me. The dialogue leads me elsewhere, in digression land, which is where the interesting secrets pierce through. So, what I really need to do is to keep up with the "plot discipline" while staying loose and updating my outline as I go along. I shouldn't just ditch the plot line, though. Otherwise, I'll  get completely lost.

When I see a piece of theatre that is rigorous in terms of plot and yet doesn't succomb to it, all the while maintening high dialogue quality, I swoon. And I want to make that piece of theatre too!  I'm in a muddy phase of writing right now - the phase where it's so tempting to quit.  But, as Chuck Wendig would say in his very useful article, "the story isn't going to unfuck itself". Thanks, Chuck. You're right. In a slightly different way, Laraine Hering says, in Writing begins with the breath: Embodying your authentic voice  - "Write. Stay with the discomfort. Stay with the uncertainty".
And reading plays and other books helps too. I'm currently reading Georg Büchner's play Danton's Death and I plan on reading Sarah Kane and Mark Ravenhill next. As Philip Pullman said at a talk I attended once:  "Read like a butterfly, write like a bee" (and watch fewer silly films/sitcoms on Netflix).