Fist of all, get help, understand that your situation is temporary and that suicide is a permanent solution to a temporary situation. Don't wait, talk to someone tomorrow, suicidal thought can magnify quickly. YOU NEED TO TALK TO A PROFESSIONAL! there is someone that loves you that will be hurt very bad if they loose you, keep your mind fixed on that fact until you are better.
As for the other issues many developers are bad at extracting their worth from a company, but remember if you don't ask no one will give it to you. Think about it this way if you are at the point that you feel like you have nothing left to loose and could kill yourself, then what do you have to loose in asking for more money and if they don't give it to you, talk to another company don't convince yourself that no one will pay what you are asking you would be surprised at how many that will if they believe that you can deliver.
You are in a high growth country where things are projected to get better and better keep focused on that.
Front-end skills are in high demand, try to find some remote US work and charge US rates, get a US PO Box and bill from that address have it forward to your address in Brazil. Charging US rates to US companies will give you the advantage of not having to find as much work.
If you are suffering from depression then take an easy project from one of your many uncompleted projects and finish it. Don't focus on the fact that you have a bunch of half implemented projects, focus on the fact that you have one project to complete look at the rest of them as learning projects that you extracted value out of them by learning.
