One word for you, Mary......WILLPOWER!
If you have a strong willpower, you can overcome those thoughts of suicide and depression. Dont let the pressures of the world force you into a situation that you think theres no way out of. Screw this world!! there is always a way out, and unfortunately, a lot of people succumb to those pressures without realizing or even trying to fight them off. Be better than that, bring out your own confidence and stand firmly on it....no one can change your mind once you've decided whats best for you (is'nt individuality great?), as long as its all based on solid, positive outlooks for your own life.
I know, easier said than done, right? Well, thats true to a degree. Example...I know a guy who smoked for 30+ yrs. tried all the various techniques to quit, yet they all failed to force him to quit. On his own willpower, he instilled the thought in his head that HE was the only one that was gonna do it. He stuck to his guns and resisted all the temptations to give in to the constant pressures of starting up again. Now 15 years later, he's still smoke-free!
Moral of the story......YOU CAN DO IT, TOO.