one thing i personally learned by dealing with people, both guys are girls who are just like what this guy sounds like...
dont count on their words. if their promises/plans arent consistent with what they are doing then dont count on it. esp, when they are depressed or have alot of stress. they could be feeling one way like they are ready to go out and spend time with others but then it hits and despite all the feeling and the talk and the plans, its so much easier to not even try anything. thats depression.
and it sounds like you really want to help him. hes going through this and that, and you are motivated and ready to help him get out of it i know just how you feel because i am the same way with others i meet. theyre lost and kind of feeling hopeless and dreadful so you sit and listen to everything they say as they vent to you and you hope that by you being around them to help is going to make a huge difference. you like them. so you want to help them and change their situation. completley understandable, and i think thats very nice.
but if he is one of those people who wont accept any sort of help emotionally or spiritually, then there really is nothing that can be done. its a pretty hard thing to accept, but of someone dosent want help, they dont want help. of course they wont ever really say it, but they do in a way, its all in their body language, and behavior patterns around you, and others like you. maybe he wants help but he feels like he dosent deserve it, maybe he feels like he dosent need help, despite drowning, maybe he feels like there really isnt a point to anything, all the help and love he can get wont solve his issues. sometimes you can never really get a clear answer to these types of things, and perhaps even the depressed person themselves dont even know the answer.
sorry to say, it sounds like this is just one of those situations thats out of your hands. your the one who is up and ready to help eagerly, encourage him and work with him through it. but hes emotionally barely holding himself together by what he is already going through, and to try to make things better takes even more out of him that he feels that he cannot afford, or may not deserve. your encouraging him, hes answering back, but not taking action. kind of like an alarm rings and the kid hits snooze for the 7th time. "just give me 5 more minutes...." he says.
in the end. its up to him. he used to be so interested, but now that hes gotten to know you, and now that he knows that you like him and you know of his depression and issues, that novelty of meeting someone new, liking them, wondering if they will ever like you, wonder what they do, all that has worn off. perhaps he feels like he dosent need to try so hard anymore because of that novelty fading away.
i think the best way for you to cope with this is to find another interest that can take your mind off of him. i know its gonna be hard, but its like beating a dead horse. and just keep a certain distance, so that you dont hurt or stress yourself over trying to hack this puzzle. if he tries to step up only when you step away then that can say something about him, if he dosent and just lets you go that can also say another thing about him.