Hey Vladimir - we can totally sympathize - that test is a bear! Don't be so discouraged, you definitely have a good attitude if you're willing to devote so much time to studying! The ups and downs of grad school admissions are definitely a roller coaster.
What you might want to do is just focus in on one part of the test first. Which type of question do you feel like you understand a little better? Are you more comfortable with a particular type of verbal question, for example? Or maybe data sufficiency or another of the quant question types is easier? Figure out which one you're better at and work exclusively on that at first. Don't worry about the others, just get really good at one kind of question. That will help you build your confidence up again.
Also if you can find a buddy to study with it might be good - you'd have a built-in support section and you could cheer each other on through the process. Talking through the problems with someone else is often a great way to learn it. You can do that a little here on the forums but it's not the same. If you are better at learning in "real time" with people around then that can be very positive. Not sure where in the world you live but maybe there's a way to find others near you who are studying too?
Please don't give up, it's definitely possible to get to a 500 level score from where you are at, people do it all the time. Lots of people bomb out the first time, it's really stressful and so easy to mess up. Please stay in touch, we want to know how this goes for you!!
EssaySnark Essays Reviewed on GMAT Club FOR FREE!