Hi

to restore your whatsapp account you must follow the following steps:
- you should delete the whatsapp program from your phone then install it again, you can download the program from this links:
- For Android system click here

- For iPhone and iPad click here

press on agree button

- Choose your country, then type your phone number and make sure that the country key before the number is correct
As shown in the picture

- You will receive a message with a verification code on your phone. Write the verification code if it is not activated automatically.
- If you do not receive a verification code on your phone, click Call me
- Write your name and click Next
As shown in the picture

and you can protect your whatsapp account by enable the secondary authentication feature by following these steps:
1) Press Settings
2) account
3) Tow-step Verification

4) Enter your password
5) Put your email, to retrieve your password if you forget it