Yeah, that's a nice first attempt for your new direction. Mandalas are great but it's nice to play with a broader language...
So you want criticism? Like specific stuff...? That's hard, since art is in the eye of the beholder. Your technique is smooth, and being at such an early stage in this new art paradigm you've entered- I think you can be pretty confident that you won't be limited by your digital skills.
You'll be your own worst critic, because only you can know what the vision is that inspired the piece, and by how far it falls short. Ask yourself, what was I trying to say here- and did I manage to, more or less? For example: as a casual viewer, I get the impression that you're showing the literal dissolution of self- the grayscale facial fragment- revealing the rich inner visionary realm. If that's the case, those flame shapes at the top might be more effective if they drifted off like smoke instead of ending like knife blades. Referring to real smoke, like burning incense or something, would help make this effect more realistic. Then, the visionary realm revealed- that might be more effective if it took up a bit more of the composition- imagine making the canvas taller, maybe by 20% or so. This would give you the headspace to go to town more with the visuals- perhaps you could bring in some of your mandala action, centered on where the third eye would be if that part of the head still existed...
I think the dense core of hyperspace matter hovering in the brain cavity is a super cool touch.
I think it's great that the head is large, somewhat monumental, and you wouldn't want to go too overwhelming with the visuals, or you'd lose that effect.- the large head makes for a strong composition and makes the sense of personal dissolution central to the composition.
Keep it up, you have both vision and skills.