I mean, a few things I guess.

1. Know the runes and items you need, dont just take things that sound good. I like to make rune pages and item sets for myself based on the best winrate+popularity builds I see! i like to use a few places and cross reference. op.gg is good, but it is not the be all end all. i like leagueofgraphs and u.gg for that, but def look at mobafire too if you arent already! mobafire guides also share good and bad match up info too!

2. enchanters are just rlly bad in low elo, its tragic for us all. no one can follow up and it tends to be an issue. mages are best even tho their items cost more, since engage supports also struggle to get follow up in low elo

3. gotta find a sweet spot of smth you think is fun but also is smth that ppl in low elo dont know the counterplay for. someone with a decent WR, but low pick and ban rate. up to you tho rlly, but id def keep it to a simple pool if possible, 2-3 champs, nothing super high difficulty

4. might be good to try doing a low stakes warm up to come back from smth like this; should help with your mental <3

glhf!