need both criticism and advice to surpass my old drawing

Hello:3 
I've not drew for like 9 months bc I was busy studying for the most important exam in my academic life,and now after i finished it I return to drawing but I feel like I've lost a lot of the progress I've made in the previous summer(which is the time when I started to take art seriously) 

this is a gesture drawings I did in that time 
[img]https://drive.google.com/file/d/1nEsHjg61WKxF3yrT6o11bWIPoiEOyiSb/view?usp=drivesdk[/img]
and this one I did yesterday so you can tell the difference•~•
[img]https://drive.google.com/file/d/1nNXpvI5Aue3-qeGDOJxYMSlm9DKEmgaB/view?usp=drivesdk[/img]
I really appreciate it if someone could tell me where to improve my drawing to surpass my old drawing and become better in general

You have a great eye for detail! These look really good. One thing I would say is to focus more on proportions, that tends to add realism to even stylized work. I would also suggest focusing on form. Shadows are a really good way to do that, but if you visualize the 3D object and how that shape exists in relation to the rest of the figure, it would lend a good amount of finesse to your art.

A lot of this can happen naturally if you draw even a little bit everyday. As someone with super demanding studies, I totally understand how overwhelming it gets. I would suggest carving out some non-negotiable time to draw. If not, what I do is carry around a small (seriously, small) sketchbook and try to draw from life in my free time. I find I'm waiting around a lot, and instead of going on my phone, drawing whatever's in front of you is a great way to practice form and shape all the time.