I can probably help you out alot since I (was) kinda in your position, only I had different upsets and I was far from the point of hoping for death(Though i'm not afraid to die either,unless its torture something)
First off, the most simple yet effective advice I can give you is to look at the positive things in your life and block out the negatives. This was one of my major problems, I always looked at things from the worst case scenario and it was hell. Eventually, you should be at the point where you can look at the positives and accept the negatives, which is a good point to be at because sometimes blocking them completely is a bad idea depending on the situation, but for the time being blocking them is your best bet. I know it sounds like generic advice but honestly just take some time and just do it, it DOES help.
I'm lazy too, but thats fine since its just a characterisitic/trait. I am lazy when it comes to doing anything for myself(i'll do it eventually tho lol) yet when someone asks me to do something i'll jump on it instantly, i dunno why. maybe its like that for you.
About your goals, well, if you can't think of any ideas that will induce motiviation other than playing for sonic times then why not do that? you are like 15 or 16 right? as far as I know life has no true "meaning" or goal other than to maybe have your own family. you are far from ready for that, so just do whatever you want in the meantime. If you like playing sonic for fast times and you enjoy it then do it, there is no harm in that since for me atleast accomplishing something gives you that rewarding feeling, which is something to be proud of regardless of what it is that you have accomplished.. If you feel that no one else cares about your sonic times odds are it isn't true, and if it is then play something that everyone else plays and do well in it(records records records!)
Getting a job isn't going to directly help you, if you don't think of a job as a "goal" nor want one at the time, well think about it- it will only make your situation much worse.
About your health.. well theres no excuses here, you need to be doing SOMETHING that involves more movement than your hand and eyes. The reason taking a walk doesn't work is because its just plain out boring probably.¦nbsp; If you like sports find one you like and thats probably many good hours a day which would suffice, do that. If you don't like them thats fine too, if you don't like them you don't have to, and don't let anyone make you think "omg you don't have a life" or something because of it. You should do what you enjoy, and no one has a right to insult you for that.
when I was 16 I was like you, I may not of been at the PC all day but I did sit around in front of the tv playing on it instead, and at one point I could not even stand up without feeling like I was going to die. That part of my life sucked, I slowly got better though and at around 17 I was fairly normal psyically, and since then I make sure to get atleast 2-3 hours outside everyday. If you like in the country like me thats easy, you can find all kinds of things to do. If you can't use your imagination =) Make believe something is there, pretend, anything that seems fun and keeps you motivated to stay active. If you are in a city, well it sucks worse there since you won't have as much ground to play with most likely but it could work if you have some friends. As an added benefit, I know my gameplay skill level has increased by far compared to had I not ever gotten outside.
And like quartz said, something will come up, just try to have fun until then, don't waste your life sitting there thinking it sucks, do something (FUN) thats the keyword here.
I hope that helps you out man, I had no idea you had felt like this, you always seem pretty happy by the way you post. if you are unsure of something still or have more questions shoot away, I'd atleast like to think I could answer any question you may have seeing as I was in such a similiar position. A very sucky position to be in I know.