550 credit score need some advice please

I have a credit score of 550 I have chime secured credit card which works good got me from a score of 490 to 550 quick. Basically I wanna ask you do you think I should sign up for credit repair company (I have 5 collection accounts that’s way to much for me to pay). Or should I get another secured credit card like you did with capital one and be patient to watch my score go up. I landed a super good job where I can afford the car I want which is $30k-$35k but I got approved for an interest rate at 23% which is way to high especially for a car that much.