HC is a matter of skill too, but you have both null and mirror which is good and you have TSS so you can kill mobs in range. But for HC it is not a “no brainer stand and tank soldier guy”. I did not die until shriek nulled me in ult SR 26 so, but I am pretty good player (3/5 rating).
Celestials should be doable, the final mega spec at least - but you have to play good of course
If you are new to the game and wanna start HC right away - I would try something else first…
If I were to play HC with this kind of build, I would focus more on armor (another dev tree) to get it up to 3000 and maybe even using the new shield that gives phys res to star pact (but then skill tree will be thin since needing to get 50 on both masteries) to get like 20% phys res, and getting more points into the berserker passives down the left side (hp regen, and dmg abs%). Maybe