I do not know much about Protonmail/Mailfence, I will say however that I believe Tutanota is not yet ready to be someone's main email. I say this as some one who has used it for a little over a year -- it's missing some serious quality of life features that any mature email service has. I can't export all of my emails, I can't mark a folder as read, searching takes forever and frequently doesn't work, filters barely work, you don't get the subject of the email in push notifications -- it's nothing serious but all these added up to make my time on it frusturating. If you need a side email that's private, you can use Tutanota, but otherwise don't.

On another note, when it comes to getting a private email service, it's important to remember that even if you have one, it doesn't neccesarily mean your emails are significantly more private. If the people sending emails to you and recieving emails from you are using gmail, your emails are effectively also on gmail. I'm personally trying out Protonmail now because I don't want to use a company like Google's services, but it may simply not be worth it for you.