Running with the vampire perk with the Cryo Cannon and the Impact Axe is a viable combination for keeping your health pool up, but you shouldn't rely on it too much. You still got to use your guns to survive. Heavy Hitter I can understand you use for high damage, but feel free to try Energy Rerouting and go with 1-2-1-2-2 mod loadout for it. You can deal a respectable amount of damage with normal shots AND be able to utilize Thin Containment Field for clearing clusters and for blast mining.
Similar to my other response I mainly took heavy hitter because I prefer using normal shots over charged shots, and wanted the extra damage and fire damage. I also didnt take tcf because I havent practiced it enough to be good with it.
TCF can take some practice, but once you get the timing right, it will work wonders for you. The best way to practice is firing a charge shot from the side and in front the mineral vein you want to mine. Energy Rerouting or Magnetic Cooling Unit will work for overclocks and the Improved Charge Efficiency mod on tier 3 is a must-have.
And if you intend on using TCF on a cluster of enemies, the trick is to fire the charged shot above them and then shoot at it to trigger the effect.
I found myself preferring to just use regular shots over charged shots with the epc so thats why I took that mod, but I'd try the first slot instead and use some charged shots, thank you.
The charged shot is especially effective because it can pass thru and just disintegrate every frozen enemy in its path. The Energy Rerouting overclock can make the charge shots a lot easier to pull off. Of course you can still use your drills to melee leftover frozen enemies for health.
I've been looking for a good secondary to pair with my Tuned Cooler Cryo, and after trying various CWC builds, I like Heavy Hitter EPC the most.
Good build.