I’ve hit a wall and need some advice

I’ve been trying to get my character to paragon 300 as well as try and finish the seasonal challenges, but I feel like I’m at a wall. I get to T4 and anything involving lair bosses or even bloodied infernal hoards on t3 feels impossible. This is the paladin build I’m using. Mainly looking for advice on if I need to change gems, runewords, affixes, etc.

https://www.icy-veins.com/d4/guides/arbiter-paladin-build/#gear,\_stats,\_gems\_and\_runes

Any advice would be greatly appreciated. I’m at paragon 230 and feel like it’s near impossible to barely climb levels at a decent speed.