if 5000 people sent me $3 each, and paid the necessary $0.14 fee for example, how come I need to pay x20 fee more than them? what the fuck for? this is completely stupid.
Every transaction requires fees to pay the miners. The accumulated sum of BTC you have doesn't automatically combine (The network is decentralized after all). Next time use Coinbase. I think they can facilitate micro-transactions for now. They will pay for the fees to combine your sum of BTC.
If you have the private key, I think you can combine them cheaply here
https://coinb.in/#newTransaction