Love, money, relationships, loss of a job, your path, your vision, your mental health. These are all serious things you could lose and in fact did lose. It doesn't serve you however, to embrace doom-thinking no matter it's heavy emotional gravity-pull. It's more about facing the worst that could happen and then test yourself how you can handle it and what you can do about it. Often writing out the worst that could happen makes you realize it sounds worse in your head than it really is, and you can, in fact, handle it.
I'm not sure what else to add. I can list more thing I could lose but that's counter-productive to just list everything and burn myself out. What I think is useful is to ask this question in various smaller limited contexts. Such as a new endeavor. In this manner you can anticipate roadblocks and obstacles. Then having considered them deeply you are less caught off guard and are able to take effective action.
Title prompts are taken from The Daily Stoic Journal by Ryan Holiday and Stephen Hanselman.