how can I create wifi hotspot on windows 7 that can be shared with my macbook?
The first step is to run the Wireless Diagnostic from the Mac since it's easy. There are iOS diagnostics, but you'll have the best luck determining why OS X won't connect to the network. From there, the iPhone issue will likely be solved, but if not you'll have a smaller problem to solve.

Option click your WiFi icon in the menu bar (place it there in network settings if it's absent) and then select Wireless Diagnostics.