Amber Portwood on Staying Sober, Liposuction & Her New Boutique — Plus Find Out Which 'Teen Mom' Stars Are Invited to Her Wedding!

"I want people to know me for more than just from being Teen Mom OG, because there's a lot more to me," Portwood tells PEOPLE

Photo: Rich Polk/Getty

It’s been a good year for Amber Portwood and it’s just getting started.

The Teen Mom OG star, who is preparing to walk down the aisle to her longtime partner Matt Baier this October, has found herself juggling quite a few projects, including a new online boutique Be Forever Haute.

“Every time people see me on TV, I always have someone asking me, ‘Where did you get that shirt or those shoes,’ and I was thinking, ‘I should do a boutique,’ ” she tells PEOPLE exclusively of how her new business got started. “I didn’t know how to necessary design my own clothes, but a boutique would be a great start. I pretty much did a lot of research — a few months worth — and made sure I had all my ducks in a row and then I went for it. I invested a very large amount of money into this boutique.”

“I’ve been from a size 0 all the way up to a size 12, and I always want to look sexy. I always want to be comfortable and look good. So I wanted to do a boutique that can fit all types of woman, because I have been every size in a way,” Portwood says. “I did a size small all the way up to a 4x. I am going to pick out clothes that are gorgeous and cute and not feel like you’re wearing a Muumuu everyday.”

Portwood admits that although she’s extremely busy with the boutique, she has found time to still plan her upcoming wedding with the help of her soon-to-be husband.

“[Matt] is completely into it, even more than me maybe,” she jokes of the 45-year-old. “He is writing down the guest list and we already have 200 people on it, I don’t even know 50 of them! Every single Teen Mom [star] will be invited. Every single one from Teen Mom 2 and Teen Mom OG.”

“I don’t know if I feel frantic or anything,” Portwood adds. “I’m kind of scared — not for any particular reason — just the fact that I’m getting married. We are on time and we pretty much know exactly what we want to do. We’re just trying to stay level-headed, because there’s a lot going on right now.”

RELATED VIDEO: Farrah Abraham Body Shames Amber Portwood After Their Teen Mom Feud — And Portwood Fights Back!

One thing the 26-year-old did insist on doing herself was designing her wedding gown.

“I am designing my own wedding dress … I just don’t know who I would want to do it,” she admits. “The style that I am going for is really ‘30s, ‘40s, ‘50s, where it’s kind of see-through but not. [It has] certain jewels on it, [is] body-forming and flared out at the end with a long train. I’ve went to a couple of stores and looked at dresses that are very similar and I got a lot of ideas.”

As for her daughter Leah (whose dad is Portwood’s ex-boyfriend, Gary Shirley), she wants a similar look for her, saying, “I think Leah should wear almost the same dress as me, but only a little puffier at the end — really girly and just right for an 8-year-old.”

Though planning a wedding, running a boutique and parenting an active daughter could be stressful, Portwood admits that she’s stayed sober through it all.

“I think now it’s been 5 ½ years I’ve been sober, I stopped counting awhile ago,” she admits. “I couldn’t do any of this if I weren’t sober. The only thing I am doing is taking medications for my bi-polar, borderline personality and anxiety. In the beginning you have rough patches, because you are trying out medications and you have to find the right ones for you, but I am doing really good … I go to the gym 3x a weeks and I eat well.”

From Coinage: 5 Financial Mistakes to Avoid in Your 20s

Portwood did reveal that she had a bit of work done to help with her weight loss regiment, but has stayed away from getting plastic surgery.

“I did get liposuction on my sides and my stomach, but not a lot. I got a breast lift a little bit — an under-cup — not a whole big boob job. It’s like a pushup bra. That’s the only thing I got done,” she admits. “I used to have an hourglass figure back in the day, but I didn’t really have it any more. So that’s all I really wanted was to get my body back to where it was from losing and gaining weight.”

“I didn’t do any major plastic surgery, and I’m sorry, I don’t really believe in major plastic surgery,” Portwood continues. “I don’t believe in plastic surgery on your face [but] everyone makes their own decisions on that. For me, personally, I don’t want to mess with anything else.”

All in all, Portwood just feels blessed to be given the opportunities that she’s had since filming the Teen Mom series.

“The one thing to always remember, is that the reality world is a gamble; you never know when it’s going to end and I feel like I am really blessed with what I have today,” she says. “I am going to use all my resources to make sure that my life and my family’s life is going to be blessed even with all the bumps in the road.”

“I just want to be a good role model for Leah and that’s another reason why I wanted to start my own businesses,” Portwood adds. “I want people to know me for more than just from being Teen Mom OG, because there’s a lot more to me.”

Teen Mom OG premiers on April 17 at 9 p.m. ET on MTV.