#1 bro if you are that depressed and down about how you look, steroid will likely only make it worse. It's not magic and won't transform you. If you run the cycle then most likely you won't transform how you want, and depending on how healthy you run the cycle, the mental effects of juice may only make the depression worse once you get off and realize you have a really long way to go.
#2 if your diet has been horrific as you say it is, you need a while of perfect dieting so your body can detox. You need to drink tons of water. Eat clean. This alone will make you feel so much better because of the nutrition, and that fact that you have control over something. You can put your mind to something difficult and get it done. Sticking to a strict diet is rough, but once you get in that groove you truly feel accomplished.
#3 get some good quality cardio sessions in. It's gonna help you cut fat, but will also help your lifts. You will have more energy and endurance which will cause you to lift more. Your core will be strengthened which will help you lift more.
#4 come to terms with yourself and the situation you are in. The only person who can fix it is you. Make getting fit somewhat of an obsession. Stop thinking I can't get in shape without some artificial aids. Think 'I will get in shape and I will not stop until I get where I want to be.' set your goals at realistic intervals so that you are reaching them and not getting discouraged.
Now I know you will do what you feel you need to do, but I hope you take everyone's advice. I know you feel you may be in a dark place, but the light is always there you just have to strive and work for it. Good luck bro. PM me if you need any help