I really don't recommend to hire those that do "Influence" for you for $5... Come on, your business is serious, hire serious micro-influencers, they charge $200, but they will do serious influence for you.
I feel your pain man. No fun when you you're spending money and not getting much back. Here's some food for thought:
1.) Paid traffic is requires budget. If you only have $XX it is not the place you want to be. Build up a budget with a job or (if you can hack it) organic traffic before spending money on traffic.
2.) Choose one traffic source. Without a budget that might mean Instagram or SEO or whatever. The source matters less than choosing one and focusing.
3.) Study your chosen traffic source. A few youtube videos doesn't cut it man... you're up against the rest of us that do this sort of stuff all day, every day. Gotta dive deep if you want to compete.
4.) Don't get married to one product type. I know nothing about the phone accessory industry, but I imagine the margins are low, the competition is high and the traffic is expensive. You can make almost any product category work, but some are way easier than others. Being willing to pivot is one of the patterms I've seen with those that break through.
Hope it helps.