He wants outside ALL the time.

So I have had my cat Bentley for three months now. He is a neutered male about one year of age. He wants to go outside ALL the time. Every day, I take him for walks for at least an hour. Sometimes two, hour long walks. Lately it seems like if he is not sleeping or eating he wants to go outside. When I dont let him out on his walk he tries to escape, looks sad in his facial expressions, and looks at me with disdain. This cat lives to go outside. The problem is, he is my cat now, and I cant just let him roam around the neighborhood unsupervised, playing in traffic, running onto people's porches, and roaming wild in the woods where there is a big coyote problem. I live in a one bedroom apartment and work at home on the computer alot during the day. This may be part of the problem. I play with him alot. He has toys, and a window to look out of. But it doesnt seem to be enough. I know eventually I am going to have to move into another place and get a friend for him to keep him busy while I am working, but right now both of us are unhappy. I can not financially afford to do this for him at this time, and I need some advise on what to do so he doesnt feel sad and trapped. When he is outside with me, he is really happy. He seems to like me otherwise and follow me every where. When I did let him out on his own he always came back, so he knows this is home. I tried just not letting him out, and that absolutely does not work. To him, that is like prison. If I ignore his cries, he takes it personally or at least acts like he does. He is a very smart and sensitive cat that loves being outside. I just dont know what to do. I cant stand seeing him unhappy, but at the same time, I can not walk him at all hours of the day. Please help.