New mom Vanessa Lachey couldn't wait to hold her newborn boy in her arms after giving birth, but says her feelings of pure joy and happiness morphed into debilitating "baby blues."

Lachey, the host of ABC's "Wipeout" and wife to singer Nick Lachey, revealed her overwhelming feeling she calls "baby blues" set in two weeks after giving birth in September to son, Camden John.

"I noticed a swing in my emotions. At this point I was sick of feeling like a milk machine," she wrote in a blog on her website. "I felt lost, unloved, alone and at my wits end. It's weird, too, because I have an amazing and supportive husband, his loving family and wonderful friends. But at that moment… I felt like NO ONE understood me."

Though Lachey says she feels guilty raising the issue when she feels blessed to have a healthy child, Lachey wrote that there was no other way besides "baby blues" to describe what she felt as her world came crashing down.

"I was feeding Camden and crying my eyes out. I felt like I had officially come undone," she wrote. "I imagined blissful days, tired nights, but quiet loving moments. I imagined family dinners with the 12 casseroles I prepared ahead of time, and a beautiful post-pregnancy glow that embodied me 24-7. But This was none of that."

Lachey said she felt like the "super woman" she thought she could be was no more as fears of not being a good mother overtook her.

"I think it's just fear…The fear of not knowing what I'm doing. The fear of 'messing up' this little boy. The fear of being responsible for a human being and not knowing any 'life' experiences to compare moments with him to. No matter how many books you read, NOTHING prepares you better than the real thing," she wrote.

Lachey explains in the blog that she left the baby with husband, Nick Lachey, and took a drive to collect herself: "I … put my sunroof down and blared the radio. …I went to Starbucks, came home, took a shower, put myself together and came upstairs to give my husband a kiss and tell him I was sorry…I was sorry for the weeks of losing myself."

Lachey is not the first celebrity mom to open up about falling victim to post-partum "baby blues." Alanis Morrissette revealed she struggled with intense post-partum "baby blues," after having her son, Ever.

"It was just a really intense time," Morissette said in the Aug. 2012 interview. "If I could share anything with anyone who's going through it, it would be to encourage them to seek help and reach out a little earlier than I did."

Senior Medical Contributor Dr. Jennifer Ashton said today on "GMA" that baby blues and postpartum depression lie on a spectrum and both are extremely common.

"If you're saying to yourself, 'Something does not feel right,' there is no shame in this game. Say, 'Look, I need some help here.' It does not make you less of a mother," Ashton said, telling new moms to consult with their OB-GYNs.

Lachey said she decided to open up about her struggle since it's "a reality for so many more women than I ever knew." She writes that she hopes other moms realize as she did that there's a light at the end of tunnel as long as you take time to get back to "you."

"It's okay if we can't do it ALL because…. we have already done so much! I needed to remember that hormones have a mind of their own, and I couldn't allow that to anchor in my thoughts," she explained.