What does Buddhism teach about fear of success?

Sometimes people have fear of success, i. e. get agitated and nervous, when, for example, * some important person behaves exactly like they wanted (and they didn't expect it), or * they achieve a minor success, which indicates that their plan is working. Think of a small business owner, who creates a successful advertising campaign and then gets upset about too many clients. What **actionable** recommendations (protocols) does Buddhism in general and Diamond Way Buddhism in particular have for people, who want to overcome such fears?