This load order probably has issues but please ignore them if you can't trace them to the arrow problem. I don't want the thread derailed. As I was saying I've had this issue before on a mage character playing vanilla Skyrim without any mods who was getting oneshot and sent to the heavens by arrows. That is why I created a platewearing melee character instead to try to soak those hits, but even then it is clearly impossible. Nevertheless, here it is:
Update.esm
Dawnguard.esm
HearthFires.esm
Dragonborn.esm
ApachiiHair.esm
ClimatesOfTamriel.esm
SkyMoMod.esm
SPIKE.esm
Falskaar.esm
FalskaarDawnguard.esp
HighResTexturePack01.esp
HighResTexturePack02.esp
HighResTexturePack03.esp
FixedEyeAdaption.esp
Unofficial Skyrim Patch.esp
Unofficial Dawnguard Patch.esp
Unofficial Hearthfire Patch.esp
Unofficial Dragonborn Patch.esp
Chesko_Frostfall.esp
Better Dynamic Snow.esp
Further Dark Dungeons for ENB.esp
StaticMeshImprovementMod.esp
StaticMeshImprovementMod-FurnitureChestSnowFix.esp
Birdsofskyrim.esp
Lush Trees.esp
Moss Rocks.esp
Real Clouds.esp
Undies Underneath.esp
Auto Unequip Ammo.esp
Footprints.esp
WetandCold.esp
SkyUI.esp
bound weapons redux.esp
hothtrooper44_ArmorCompilation.esp
SkyRe_Main.esp
SkyRe_Combat.esp
SkyRe_EncounterZones.esp
SkyRe_EnemyAI.esp
SkyRe_EnemyScaling.esp
SkyRe_StandingStones.esp
SkyRe_Survivalism.esp
quest_andtherealmsofdaedra.esp
tos_granitehall.esp
quest_nomercy.esp
quest_pitfighter.esp
quest_pitfighter_dlc01.esp
quest_sorcery.esp
quest_seaofghosts.esp
quest_thebiggertheyare.esp
Undeath.esp
wyrmstooth.esp
AchieveThat.esp
Civil War Overhaul.esp
Dawnguard - TJofP.esp
tos_amber_guard.esp
tos_laintardale_hf.esp
tos_oakwood_hf.esp
DragonCombatOverhaulDragonborn.esp
ClimatesOfTamriel-Sound.esp
ClimatesOfTamriel-Dawnguard-Patch.esp
ClimatesOfTamriel-Dragonborn-Patch.esp
Imp's More Complex Needs.esp
BabettesFeastBalanced.esp
CookingExpanded.esp
Real Wildlife Skyrim 0.1.esp
Brevi_MoonlightTales.esp
apocalypse - the spell package.esp
BFSEffects.esp
Locational Damage.esp
Acquisitive Soul Gems.esp
3DNPC.esp
Gri_BeastFeet.esp
SkyRe_Races.esp
getSnowy.esp
WATER.esp
WATER Plants.esp
WATER DB Waves.esp
ReProccer.esp
No Killmoves, No Killcams, No Killbites.esp
WATER Misc.esp
Bigger and Boulder.esp
Vibrant Auroras.esp
Enhanced Distant Terrain 2 DB.esp
Enhanced Distant Terrain 2.esp
FireAndIceOverhaul.esp
Unique Grasses.esp
hothtrooper44_ArmorCompilation - TJofP.esp
Predator Vision.esp
Helgen Reborn.esp
Bashed Patch, 0.esp
BrighterTorchesBiggerMagelight.esp
The Joy of Perspective.esp
TJoP - Transitions.esp
EDIT: The only one I've really thought about is Locational Damage but it happened to my old mage which didn't have this mod enabled, and that mod also has an effect on melee damage which isn't going crazy at all.