It's Unearthed Arcana content, but the Artificer Battle Smith allows for +Intelligence to weapon attacks and damage which is a perfect fit for both GWF and Elven Accuracy.
Battle Smith is proficient with martial weapons and medium armor, which is a good start, but things just get better from there. Battle Smith gets free magic items, some healing, expertise in tools (including thieves' tools), and if your DM will allow it firearms. The Arcane Weapon spell allows you to use a greatsword and have a standard attack at +6 for 3d6+4 at level 3 (plus potential Booming Blade/Green Flame blade damage). At that same time your Bonus action Iron Defender bite is +4 attack for 1d8+2.
I recommend High Elf, with point buy stats of INT 16, DEX 14 (med armor cap), CON 14 (HP+saves), and rest into WIS or CHA as you see fit, dumping STR.
It's your call on GWF or Elven Accuracy at 4 or 8. But with class included Iron Defender companion you will be able to set up flank or help action for advantage. You also have Faerie Fire as a spell, but I recommend Arcane Weapon. There is an added defensive bonus too, as the Iron Defender will impose disadvantage on anyone attacking you if they are the ally you use to get flanking advantage.
With High Elf sub-race you can snag Booming Blade/Green Flame as your racial cantrip. The Cantrip isn't that great since above 5 this class gains a second attack that is almost always better. Alternately you could sub race into Eladrin for Fey Step, though the potential of War Caster later might mean sticking with the cantrip melee attack.
At level 8 you finally have both GWF and Elven Accuracy: 2 attacks, +3 hit rolling 3 dice, 3d6+14 damage, with an additional 2d4 on the first hit from Arcane Jolt that also heals for 2d4. That's barbarian level damage. You have 59 HP and 18 AC due to the free half plate +1. You can blind an attacker who hits you as a Reaction once per rest using free +1 Radiant Weapon. Your Bonus action can be used for an Iron Defender bite at +5 for 1d8+3 if you aren't using it for GWM bonus attack. You have 4 first level slots and 3 2nd level slots that can be used for healing or utility (though the above damage numbers use Arcane Weapon). If your enemy is harder to hit, consider Haste instead of Arcane weapon after level 9.
At level 12, look for a half feat to take your INT to 18, for which I recommend Keen Mind or Observant. Your Arcane Jolt is 4d4 and your free items are now +2. At 16 take INT to 20. At 19 consider War Caster to bring Booming Blade back into relevance and pick up advantage on CON saves for concentration, or look at Tough for extra HP if you haven't found a Amulet of Health. At 20 you can attune to three extra items and you gain +6 to all saves.
I don't recommend multiclassing since the level 20 ability looks good to me, but if you know your game won't hit that level I could see a few options: a 1 level dip in Forge Domain Cleric for heavy armor (allowing you to dump DEX) and healing word; 3 levels of Fighter Champion for Improved Critical, Action Surge, Second Wind, and a fighting style; 2 levels into Wizard for War Magic's Arcane Deflection, Shield spell, and INT to initiative.