TAL and Pakistan will be the reason, but 2 years is a very long time. It's crazy as you couldn't adjust status anyway through your brother, and would be several decades away from a visa via him.
You can file WOM yourself, there is a guide on here that you can use by a lovely forum member that's done it themselves and helps others - have a hunt and hopefully you'll find it.
You can try ESTA, might want to give that a go first, but you will have to declare the previous denial.