I've been through the exact same thing. I've realised that you have to create short term goals that relate to your long term goals, and both of which need to be detailed. The more short term the goal is, the far more detailed it needs to be. For example I want to get into a top law school to do my masters. I first figured out the mark percentages I would need, and there after I focused on the exact study plan I would need to follow for my upcoming test in order to achive those marks. Focus less on the precise details of the future plans (which can easily change due to unforeseen circumstances) and focus more on the short term which is more in your control and which you're confident you can achieve, giving you more clarity and less anxiety. Clarity counters anxiety.