Coming from a very short, scene and dialogue oriented style, I struggle with this too. I'd argue that sometimes you want brevity and a few quick lines of dialog between two characters are all that is needed to carry the plot forward.
But since managing the pace of a story is a whole other can of worms, I'd just leave her some suggestions to add more meat to your descriptions; at least, the same things I follow when I'm stuck in your situation.
this is probably an advice heard from Brandon Sanderson (either from Writing Excuses or his video lessons on youtube). The point being, most human beings have five senses. We are always subconsciously aware of what is happening around us thanks to those five "channels", but as writers, we often forget less "direct" senses like smell, touch and taste. Hearing gets kinda a bad treatment too, since it mostly comes in handy where's dialogue to be heard. But dialogue doens't happen in silence - silence, truth to be told, is a rare commodity.
So, sensory data can be used to convey the idea of a place or of a situation. From a first person POV, this can be easily done (since you're describing what your character is feeling directly).
To wrap it up, if you want to add more beef to your descriptions, include sensorial data from all the senses. It works and it adds immersion.
As above. When two people speak, a lot of the communication travels in a non verbal level. Everything we do carry information - from our body stance to the tone of our voice, from where we are glancing at to what we are doing with our hands or feet. This is, more or less, a corollary of the infamous "show don't tell rule". Often, a line of dialogue will look like this:
"I don't want you to leave" Martha said, nervously.
but if you're going for a more lenghty description, it's more rewarding to show the reader that she's nervous through her behaviour, rather than just shorthanding emotions like that. Consider:
"I don't want you to leave", Martha said in a quiet, almost whispered tone, as her gaze raced to the tips of her shoes. He noticed she was fidgeting with the lower end of her shirt. Her white, long fingers were tugging the cloth so harshly that it seemed on the verge of being tore apart.
Of course don't take my extract as an example of superb writing, since I'm pretty sure it's not, but it is an example of showing, in a way. The audience knows what a nervous person will look and sound like: if you show a character acting that way, they will make the connection. And even possibly bad, possibly cliché descriptions like mine are somewhat more informative than a single adjective or adverb.
Write first, return later
This is something I often do when I'm not in the mood for lenghty descriptions or well crafted sensorial hints. Sometimes, it's perfectly fine to drive the story forward and to just zip from point A to point B. Learn to write it down even if you know it's not the best you could write.
One of the most useful things I've learned nowadays is that I don't have to write it perfectly the first time. If something doesn't feel right as you write it, but don't know how to fix it, it's way better to avoid getting stuck and go on. Just take a note and fix it later.
Personally I mark in yellow on my word file everything that feels odd or needs more work. This way, when my eyes scroll down the page, I see those yellow stains and I'm inclined to go back and see what the problem was (you could always leave a comment also, if need be). Those days when I don't have the strenght to write forward, I can always fix those yellow marks, and it's somewhat rewarding.
This is somewhat akin to editing, of course, except that you don't have to do it on your second draft. Leaving marks and notes as you go forward will help the revision process later, however you do it. This, of course, is more a general advice, but I think it's relevant as you can always write quick dialogues iff you're in the mood for it and work on expanding later.