A few things about this.
Let me start by saying that this is in no way a criticism of Jungle, nor am I saying that this is poor advice. However, I am saying that this advice is difficult to follow and may not lead to the goals it is trying to accomplish.
I've done all of the steps that Jungle recommends and I've failed--at least in my view I failed--countless times. When "being yourself" and "going for it" doesn't work you feel like shit. You can try to congratulate yourself for trying, but that honestly won't mean much. If you're anything like me, you'll still feel like shit. On that note, it's pretty hard to approach a person rationally and logically and separate yourself from your emotions, when what you're doing--talking to and trying to connect to another person--is an exercise that is inherently emotional.
Furthermore, even if you're the most confident and self-assured person on the planet, you'll still face rejection. Let me be clear, I'm not saying you'll face rejection because I think you're a bad person or anything, but because statistically speaking you are bound to face rejection at some point, if it hasn't happened already. And when it does it will suck.
I do think that Jungle's advice is good in terms of working on self-confidence and starting relationships--friendship or otherwise--honestly. However, I don't think it really applies to "picking up girls" as Jungle implied at the start of his response.
I think the nature of your problem with speaking to women is a difficult one to give general advice for because there is no "general advice" for getting along with other people--men, women or otherwise.
Unless you're literally going to pick up women--in which case I recommend daily squat exercises (you'll want to lift with your legs) in addition to any upper-body work outs--I think you're out of luck, as no two people are the same. What works for me may not work for you. Furthermore, since we're adding other people to the mix (the men and women at your workplace) that further complicates things and makes applicable advice doubly difficult to give.
I think the best advice you've been given has been by DanielLewis. If you're struggling with making connections in general, you may want to start with lower stakes. Try to make friends with people before you shoot for marriage. And try not to compare yourself to other people. I say try, because it's difficult, if not impossible, not to.
I think that if you stop focusing on gendered relationships geared towards romance and broaden you scope to people with similar interests who you could have fun with, you'll feel a little better. If nothing else, if you make friends with people, they may have friends who are girls that they could introduce you to.
Sorry for how long that was, and I hope I didn't upset anyone.