The thing is, both blockchain and blockchair says my wallet has 0$. That's not the case. I have some money in it.
As stated by jackg in the first reply, you are probably searching a wrong address.
Your blockchain wallet is a HD wallet including multiple addresses.
Every time you make a transaction, the remaining balance will be sent to a new address called change address. If you have made a transaction, your remaining balance should be a in new address. I guess you are searching the address that you had deposited to while your fund is now in a new address.
In your blockchain wallet, go to "wallets and addresses". You will see all your used addresses.