I think the key word in your definition is "too" but I'd add more specificity to it: "you want something from me, which I'm not interested in giving you, and you're not reacting to my negative cues by backing off."

This may still be too general, as there are plenty of scenarios where this would connote "annoying" rather than "creepy," like with a persistent salesperson.

Perhaps it could be more accurate yet by adding "and I'm worried you may try to take it against my will, and have a chance of succeeding." to the end. That would cover, for example, noticing some masked figure sneaking toward your house with a crowbar.