Your fear isn't completely irrational, but not going outside anymore because of it would be (imo). Learning how to avoid them, or find them, or remove them, or spot symptoms (all in that order) should make the chances of any serious damage quite small. E.g. people often seem to forget it takes time, up to many hours, from a tick landing on your clothes to actually bite. (anecdotal, but I've spotted tens of times more ticks on me than I've actually been bitten). That is already quite a barrier: proper clothing + knowing how and where to check can reduce the chance of getting bitten. And even the, not all is lost. As it takes again many hours before any possible disease transmits. If there is already a disease, to start with. Since you're talking about the Netherlands: there's quite a difference between areas when it comes to rick of ticks actually carrying Lyme, see https://www.tekenradar.nl/ for instance.