The perspective look correct, but you seems to lose it when you start drawing organic forms, like the trees. Think as them as geometrical forms too, construct them as any other part in your draw, then just add details to make them more organic.

Hey there! Nice job! I love your colors, but I think you should try a bit less messy approach, maybe try to use a bigger brush while applying colors. Also, don't be scared of mixing your values, it helps a lot if you start the whole painting with a light blue, or orange wash (depending on the sky color), because it will help unify your colors later, also you won't have random white spots next to your lines. Lastly, on your second image, there is a corner and it's full of tangents. Even though those things exist in real life, design-wise it's terrible, because it flattens entire planes. To avoid these tangents, you can afford to break the rules a tiny bit and just move the lines away from each other. Hope I could help! Keep up the good work! :)

this may be due to lighting/ mood giving the feeling of disconnection with what you may have seen in your imagination. this emotion ive found is often present at the start and if lost i recall it with my eyes closed not logically with the mind if that makes sense. if that does not work ive found that that emotion then is on the other side of the fence of adding lighting that coveys the mood i was going for that i just give a name to i.e dramatic / mysterious / sad . if you dont mind i can do a slight digital overpaint with some lighting on it.

For me I find that I lose the expression when I hit a technical wall. When you start out, it's all potential. It feels amazing and exciting to you (but not to anyone else). Then as you work, it becomes real. You realize how bad your art is compared to how you pictured it in your head. A lot of art schools these days say technique doesn't matter, and that it's all about expression. But in my opinion, technique is the vehicle for expression. If you are having trouble expressing yourself, it might be because you lack the visual vocabulary necessary to communicate your intent. So when this happens, I like to ask myself "what weakness does this reveal in my art?" And then I target that weakness with studies and exercises. Then try again, getting better every time