If you are being stalked, these are a number of actions you can take immediately:

Don’t react
The stalker will see everything you say, write or do as a reason or invitation for more contact. You can send him a clear message once that you no longer want contact, and after that you won’t react to anything.

Block the stalker
Block the stalker in your phone, mail, whats app etc. use blacklist apps
With this app you block the stalker for everything at once

Disable the location determination
For example on Facebook, when you post a message, it may be mentioned where you are at that moment. This must of course be disabled.

Be careful on social media
Also make sure that you do not give any information about where you are, or where you live with your messages and photos on social media. It may be wise to take a break from social media. Every message the stalker reads can trigger curiosity or a reaction and fuel the obsession. That goes a long way, of course, but when it comes to your safety, don’t take any risks.

Pick up a second phone
You can change phones, or take a new number and keep your old number, so the stalker doesn’t immediately realize you’re not using that phone anymore.

Make a file
Take screenshots of everything, and put those pictures in a Word file, with date and explanation. Don’t put the stalker in your phone with his or her name, but let the number appear on the screenshot, so that the screenshot doesn’t show the name, but the number. Then it will be more difficult for the stalker to deny it later on. Otherwise the stalker may say that you staged it yourself. You can record conversations and mail them to yourself. You can also send voicemails to your own e-mail address.

Have important information at hand
Make sure you can call the important numbers (police, 112, family) quickly and blindly. Make sure you have the numbers somewhere, in case your phone doesn’t work, or learn them by heart.

Inform third parties
Make sure your work, family, friends and/or social workers also have each other’s details. Make sure they know who the stalker is and tell them not to just take things for you, or give information. Make sure they know what to do if, for example, you are not at work at the normal time. Don’t be afraid to ask for help. It really isn’t a lot of trouble to walk to your car, for example.

Check your own personal data
Regularly check with companies (such as your telephone provider) whether your details are still correct. The stalker can report a change and then receive the invoice and find out your address or phone number.

Secure everything
Change all your passwords. Not just the last digit, but all of it. Don’t use control questions if you can’t remember your password.

Make a declaration
If you are in doubt about a filing criminal charges, you can at least report it to the police once. Then a mutation will be made about it in the police system. If you report it later, the police can invite the stalker for a Stop Talk: a warning talk, in which the stalker is summoned to leave you alone. (This summons is important for the later procedure. A lawyer can also send you a summons). Stalking is a complaint offence. If you report it, you also have to file a complaint, which means that you really want the stalker to be prosecuted.
Deliver a proper file to the police, with everything you have kept. Indicate what you think the police could do to trace the stalker (if the stalker is anonymous), or how more evidence can be collected.

Listen to your feelings
It may all seem very exaggerated, but it’s better to take your fear seriously.