Former MTV "16 and Pregnant" and "Teen Mom" star Amber Portwood has just released a provocative, tell-all book, "Never Too Late".

The memoir details the 24-year-old's troubled childhood, rise to fame, substance abuse and addiction, turbulent relationship with the father of her daughter, incarceration, and redemption. "Never Too Late" is the Christian hymn "Amazing Grace" epitomised.

In an exclusive interview with Christian Today, Portwood discussed those dark times, her hopes for the future, and how she pulled her life out of a downward spiral fuelled by anxiety, depression, and addiction.

Christian Today: "Never Too Late" details so many personal struggles that you and many others have faced—childhood trauma, destructive lifestyles, suicide attempts... In your darkest moments, what kept you from losing hope that things could get better?

Amber Portwood: My darkest moments were probably in prison. The main thing, along with many others, that kept me going is thinking about [my now five-year-old daughter] Leah, and how I hadn't seen her in such a long time. I'd only seen her three times while I was in there. I knew that I just wanted to give her a better life, and a better life than I had also.

Also, you see so many women in [prison] that just lose hope, and you see how sad they are. There's a lot of women in there that have been in there for so long, and they really teach you strength.

A lot of people told me before I got out, 'You have to help others so they don't go through what we go through in here.' I'm determined to do that.

CT: Do you think that being on reality television contributed to your problems?

Portwood: I feel like I didn't have the tools to handle the notoriety and the fame. I was too young to understand exactly what was going on around me, and too naïve. It really took a lot of soul searching and a lot of hardships to get me where I'm at today. Now I'm sure of myself. I know myself. I know my weaknesses, I know my flaws, and I know my strengths.

CT: "Never Too Late" also emphasises the need for forgiveness... forgiving other people and forgiving yourself. How have you worked on repairing relationships with those closest to you?

Portwood: It was a bit of a struggle. Before I got out [of prison] I was worried about even looking at my family in their eyes. I put my family through so much pain, I didn't even know how to rebuild it. When I got out, it took a lot of communication and spending time to show them, 'This is me today. I'm not the way I used to be. I'm here, and I'm present, and I love my family.

I don't hang out with any of my friends before I went to prison. You have to change your people, places, and things, and I did all three. All I do is spend time with family now... I moved away from Anderson [Indiana], 30 minutes away to a little town... and I pretty much changed my whole life... the way that I think, how I do things, what I do... it's what keeps me on track.

CT: I know your daughter was a huge inspiration for you to turn your life around. How is she doing and how are you repairing that relationship?

Portwood: We actually are doing amazing. In the beginning it was rocky because I was learning everything new about her. It was a little rough, but we were learning each other again. After a couple months our relationship was really good, and now it's great. Now it's normal again.

We have a great love for each other and it's really strong because I was gone for a year and a half, and I never want to lose her again. And I know she has to feel some way about that too... she never wants to lose her mum again, so we just keep each other close.

CT: You have spoken about pursuing higher education. What are your plans?

Portwood: I want to go for sociology; I'm actually starting in the spring. I think sociology would be good because I'm learning about people and their environments, and why we are the way we are. For me wanting to open a rehab, I think it's a key thing.

CT: What do you have in mind for your rehab facility?

Portwood: It's going to be sort of a boot camp-rehab. I feel like, for addicts... we have a lot of excuses. Sometimes it takes a little kick in the butt in order to move forward. It's going to be counselling, everything you can think of that can help somebody, I'm hoping and wanting to put in my facility. Maybe it's not going to happen very soon, but in the end, before I die, I know that I will have this going on, and it will continue.

CT: MTV recently announced that there is a new reality show coming in 2015 with yourself and fellow "Teen Mom" castmembers Catelynn Lowell and Maci Bookout. What can you share about that?

Portwood: I think people are going to see a different light, this time, of all three of us. We're at different parts of our lives, a lot of change since we've been off TV, and hopefully I can show my fans where I'm at today, and how I've changed. You get to see the kids grown up and talking... it's great. We're filming now.

CT: So many other young people struggle with the same issues that you have. What is your message to them?

Portwood: This is going to sound really cliché, but just know that you're not stuck. Know that this doesn't have to be your life. It is never too late to change. It takes a lot of work and a lot of strength, but I don't think a lot of people understand how much strength they actually have. Sometimes it takes going through really bad situations to show them. If I could say anything, I would tell people that you are stronger than you think and you can get through this if you want to change. You have that choice in your life.

Amber Portwood's memoir, "Never Too Late," is available now in online and in physical retail stores.