I'm sure someone is going to type up something that is worth the read. I'm not really good at advise on life. I feel like I haven't experienced life yet.
But i'll tell you what I do know, and that is that you're not alone. Everyone on this forum has been depressed at one point or another. Some of us, we are just depressed more then others, and that's okay. But when you start thinking about these suicidal thoughts, that's not.
Suicide is a selfish act. You have a new nephew coming and you want to be there for him, correct? You have a twin brother, that probably wouldn't be able to look at himself in the mirror without thinking about you, trust me, I know. That alone should be enough for you to stop thinking about those horrible thoughts.
You know what you want to do with your body, you just need motivation to do it. I suggest using this forum as motivation. Use your PPR as a workout diary. Take some notes on what you have done, post some weekly improvement photos and/or get involved on one of Spectre's threads on working out. I find that when I'm trying to work out my body, I tell people and if they are noticing me not doing it, it embarrasses me. That is my motivation, not letting others down, while continuing to improve myself.
I'm here for you, as always. You have my number and you know where my inbox is.