Heavies need something. It's called squad support.

A heavy is much harder to kill when it has a logi and other squad mates behind it.

A heavy with uberbuffed HP and a core focused repair tool locked on it while it stands on a bed of triage nanohives would be nearly impossible to kill.

Well lets see,
It takes 2-4 shots with a sniper rifle to take down a heavy whereas I take down anyone else with 1-2

It takes 2-4 times longer to kill a heavy with a AR

Heavys are very resistant against splash-damage

A heavy can survive a grenade that would take ANYONE else out

I'm pretty sure that easily qualifies as "resistant".
What it sounds like you want is "bulletproof" which ain't gonna happen.

I can't and won't vouch for the intelligence of my enemies on the field but I use my militia heavy forgegunning suit frequently and have noted that, minus any flux grenades, I can survive to the extent that I just listed. Even with militia I have survived attacks that would have taken out any of my other suits long before, and by no extent am I anything special in a heavy suit.
What people need to realize is that the heavy, like any other suit, has a role on the field and a lone, roaming tank is not it.
If you lone-wolf as a heavy you will get ****** up. Loosely, a heavy is supposed to:
A. Lead the charge with support from behind, that means easy logistics access to fall back to while for iron a fearful barrage of hmg fire, or
B. point defense: lock down one position with a squad.
A heavy has many strengths if you play it right, just like any other suit. I have seen well coordinated groups of heavies+logi dominate entire games and seen it enough to know that they are PLENTY resistant in the right circumstances.
So I'll say what many have already said before, just because you suck at a fitting, that does not necessarily make it UP, nor the weapon you are getting repeatedly boned by OP.

That sounds like a heavy's wet dream. Unfortunately that probably happens like 2% in public games. Majority of players at AR users, and even then I rarely see nano hives lying around. Militia grade AR's can tear through advanced level suits like butter and they are not afraid to charge a heavy on a 1 vs 1.

THANK YOU!

Jesus christ it's getting irritating that while a dude with a big ass machinegun can kill me, a turret mounted jeep can kill me, and at the same time some dude zipping around the map with a tiny ass assault rifle can kill me IN THE SAME AMMOUNT OF TIME. Don't **** this up CCP. There's still time to fix this ****. Just increase the heavy suit prices or skill needs or something. Damn.

Or give us more medium slots.

I can assure you, given how often I am getting taken down one on one that it really can't be that hard. While I may be a militia heavy I'm still carrying around 900hp, and I just melt under AR fire, I've lost CQ DPS races with AR's when we've both started shooting at the same time.