Atomic DPS

The reason you are not running out IS your loadout.
Thats built for range and the power costs are MUCH lower.

If I was to guess OP is Atom Splitter, Neutron Bom, APA, Robot Sidekick and Geiger Blast.
That is a melee loadout that will produce much higher damage than yours.

There is a way to do it but you have to adapt a bit and use different artifacts & even then its power hungry...moreso than any HL rotation

What changes from this loadout that I passed is Atom Splitter that I use Nuclear Burst and Geiger Blast that I am using Heat Vision, I used this loadout melee for a long time, and I still use it because I have an armory for it, putting Thermochemical in place of Neutrom Bomb and, in the same way, I never had any problems, by the way, the power is almost infinite even making loads of Atom Splitter and Thermochemical and using GB all the time, I just changed because in raids this melee attack is complicated and the loss of damage, it is not significant by the amount of falls that raid bosses make.
Another thing I don't understand is why I insist on APA so much, since Electron Flare has less cost, same cooldown time, activates the aura and still does DOT, but ok, I say again that regardless of using Neutrom Bomb and Nuclear Burst or Neutron Bomb and Atom Splitter, my power bar doesn't end easy.

With HL, there's no way, most of the times the power doesn't even use a complete combo, apart from the damage, which from HL is too difficult to do the minimum that is considered acceptable

APA is a crit boost, that's why you use it.
Electron flare does activate Aura, but its such a weak for not with using.

Simply getting close and using a range loadout does not equal melee rotation. As for your HL comparison, its simply false.

I main HL and using top end melee with whips clip combo into dervish isn't 1/2 thia bad and will put out better damage.

If you're using atom splitter and Geiger blast while having "almost infinite power" you're not clipping properly to maximize damage period.

Well, for me it works more to have power to continue attacks than to exhaust the power to gain a negligible 2% critical increase with a white mod in the head slot.
And HL's statement is not false for me, my mighty damage is practically nil, almost nothing, with precision it is much more consistent, it is not OP but it is much better.
You go back to talking about melee loadouts, which do not work on T9 or T10 raids, whereas the medium or long range rotations are the ones that best fit those raids you seem to ignore.
Ligh at range is a great problem.
At least that's what I've been experiencing.

This is a possibility, I admit that I was never able to understand the principle of what they call "CLIP" and doing them is strange, so I don't do them with professional efficiency or impeccably with all powers, I say however that my damage is not bad, it is enough for me to adjust and be able to close any elite instance which is much more than you can talk about most of the game's dps today.
In any case, today I decided to change Electron Flare for APA and, in fact, my power starts to drop a lot, it's still not bad, I can do some rotations, but the difference for Electron Flare is huge.

I think we've derailed the initial question from OP, but I also think we've hit on why and what can or cannot be done. I'll end with this response to you.

Melee for Atomic is MUCH different than HL, as your (2) main combos will hit at a fairly safe distance. BOTH of these are easily done in the last (2) DLC's. Light (which I main) also can do midrange using (p)ram (c) whipsthrach clip for decent damage and on single target is one off the best might based DPS in game.

Electron Flare looks weak because half it's damage is done upfront in a single burst. It's a 7 or 10m range ability (can't remember atm) so you have to be in melee range to use it.

Also, if Geiger blast is killing your power bar, you can use Sonic shout.

I don't think it's much either but I doubt it's anywhere near their radar right now. This is just on of those situations where you have to accept the things that are out of your hands and change the things within your control. They ain't changing this any time soon.

On my atomic alt, both my DPS loadouts are on the power hungry side but they're easily manageable with a decent troll or the alert roleless buff. I run Tetra, Solar Amp and Philosopher's stone and all my blue generator mods are health for tanking. My melee AOE loadout (Atom Splitter, Electron Flare, Nuclear Burst, Unleash Antimatter, would probably be troublesome if I needed to DPS adds for longer than 30 seconds but fortunately their tends to be little breaks in between add mobs and they rarely take more than 20 seconds to kill if that. My ranged boss ST-ish loadout (Neutron Bomb, Irradiate, Heat Vision, Geiger Beam, Electron Flare, Atomic Blast) seems to be fine on power in long boss fights

I would also echo LT's suggestion of dropping robot sidekick but I know you said you're attached to it. I know it's much easier said than done but perhaps if your not already running grimorium, switch to it on double artifact xp weekend and get it to 200. That'll take away the 25% power regen penalty.