We tend to think of ambivalence as a small thing - "Should I have a donut or danish, I can't decide!!!" - but in the realm of life choices, it's huge. The cliche that you can't move in two directions at once is absolutely true, and the people I've seen who were most stuck in their lives or careers were those caught between conflicting values or ideas, such as:
"I want to do well at my career, but don't want to get involved with dirty office politics."
"I want my novel to sell well, but don't want to do any boring marketing."
"I need to market and sell for my business, but am terrified of rejection."
"I want to live my life according to my unconventional goals and values, but also have the full respect, understanding and support of my conventional family."
All of the above are examples of dichotomizing, where you're reducing a complex, nuanced situation to polarized either/or options. (Notice how the adjectives only serve to exaggerate the polarities: "dirty" office politics, "boring" marketing, "full" respect.)
Ambivalence is powerful because it is usually fear-based: you crave a particular outcome, either don't think you can get it or are afraid of it, and develop a thicket of compensatory biases and rationalizations.
Ambivalence also usually happens subconsciously or semiconsciously; and the sufferer, like most underproductive people, is usually severely undermentored. The absence of insight and support leads ambivalent people to bounce around from idea to idea, opportunity to opportunity, and plan to plan - or to cling to old, unproductive strategies. From the outside, their behavior appears irrational and self-sabotaging, but viewed through the lens of fear it often makes perfect sense.
The solution to ambivalence is to (a) identify and cope with your fears, and (b) "soften" the dichotomy so that you can locate the productive space where your values and capabilities are congruent with the realities of your situation. For example: there's a big difference between the emotional intelligence and relational competence most jobs reasonably require, and "dirty office politics"; and you can find your productive space somewhere in that space. You do all this through journaling and talks with others, especially mentors.
Please note that this process is NOT about rationalizing behavior you truly deplore, but attaining a more nuanced perspective that yields more options. Like all growth work, it can be hard, particularly at first, but it's totally worthwhile.