Just announce you would be taking a break in 2-3 weeks. Not only does this give them notice to be better prepared for your absence, this also helps mental issue

Just announce you would be taking a break in 2-3 weeks. Not only does this give them notice to be better prepared for your absence, this also helps mental issues (personal anecdote), since you can now feel relieved that very soon you'd be going on a vacation, which gives you some energy to get some work done before leaving for the vacation. I don't think you need to tell your employer the details. Just say you need a vacation. Also, a lot of us go through this. I hope you don't feel alone in this. Best of luck!