First of all, suicidal thoughts are very serious. Many universities have counselling centres that are free for students. Walk in and tell them you've been contemplating suicide and they will get you immediate help. The International Suicide Prevention Wiki might also help you find resources in your area. If nothing else works, go to the emergency room. Suicide qualifies as an emergency!
Next, be honest with your adviser about what's going on. If you've been avoiding meetings, it's possible that he thinks the worst: you aren't interested in the work, or you're lazy, or whatever. If you tell him that you're depressed and struggling, he will be much more sympathetic and will try to help. (You mentioned that he's already trying to help, but if he doesn't know the real problem, his help might have been ineffectual.) If you don't think you can say it in person, send an email.
Third: curing burnout. One common suggestion is to take a vacation, but I don't recommend this. If you're already stressed out about the work you aren't doing, sitting on the beach thinking about it will probably make it worse. I would instead suggest diving into something totally new, and preferably not related to your thesis at all. Learn how to make a perfect omelette, or read a photography book and go out and practice (even if your only camera is your cell phone), or learn how to change the oil in your car. The specific thing you learn doesn't matter that much as long as it's new to you. Universities often have clubs for people interested in rock climbing, chess, learning languages, you name it, so you might see what your university offers. This can also help you make friends -- isolation is a big problem for grad students and can contribute to stress and depression. Do your new activity for a week or two and you'll probably find yourself getting interested in your thesis problem again.
Try to exercise and eat reasonably well. When you're depressed, exercise is the last thing on your mind, but even a walk around the block can be helpful. Eating nothing but ramen is depressing in itself, so although you might not have a lot of spending money (I don't know exactly what your scholarship is paying for), buy ingredients for some healthy meals if you can. Fruit, vegetables, whole grains, lean proteins, etc. If you don't know how to cook, make that your project.
Finally, to echo F'x, remember that the worst case scenario is manageable. If you are truly miserable, dropping out is an option. The completion rate for most grad programs is low, often in the neighbourhood of 50%, so many other smart, hardworking people decided it wasn't for them. There's no shame in that.
I hope some of this advice helps you. Good luck. You aren't alone!