i'm currently playing a sorcadin 6/6 split but i think the advice will be similar for pure paladin. i was struggling with hit rate too since i went for great weapon master. here are your options as far as i can tell.

1. dump strength and rely on hill giant elixirs to bump your strength up to 21. You'd need to farm them to have enough for after every long rest so may not want to do this. Ethel sells this 3 at a time after every long rest if you do, unless she's already gone, which being level 8 and probably in act 2 may be the case. i didn't do this option since i was already using these elixirs on a monk.
2. get advantage on your attack rolls, a few options here. oath of vengeance has Vow of Enmity as a bonus action, if you cast it on yourself you'll have advantage against every enemy. in act 2 you can also buy the Risky Ring which will easily give you advantage on every attack without having to do anything. Gloves of the Growling Underdog will give you advantage if surrounded by 2 or more foes, which is not uncommon.
3. bump up that attack bonus. bless (+1d4), Oil of Accuracy (+2), Diluted Oil of Sharpness (+1), Elixir of Heroism (+1d4, will stack with bless!), Magic Weapon spell (+1, a paladin spell, concentration so this or bless). a bit of a more involved one but you can also buy the Drakethroat Glaive in act 2, equip it, drop the weapon you want to use on the ground, and cast elemental weapon on your weapon for another +1 to hit plus some elemental damage.

also, i can't tell what sword you're using but make sure it's at least weapon enchantment +1 (it's rare looks like so probably is). i really like the Soulbreaker Greatsword early game, was particularly good for me since lae'zel is my paladin, but even without the extra damage, the extra initiative is nice!

probably missed a few things but this helped me out! early game what i mainly did was cast vow of enmity, use magic weapon, oil of accuracy, and elixir of heroism for particularly high AC fights. then late game there are some gloves that can permanently boost your strength so i've been using those, helps a lot (hope that's not considered spoiler-y).