I don't think there's anything unhealthy about writing something that's highly personal. Where would motivation come from if not personal opinions, experiences, concerns, and wishes? Figuring out your opinion about some issue and stating that opinion through your writing or other art is a large part of creativity.

Your issue is actually fairly common.

Be glad you have the self awareness to realize this yourself, before others point this out to you.

The latter would be concerning, if others see you in your work before yourself, and if you agree with them or not.

So, in general, no, it should not be concerning, nor surprising.

(Unless you didn't know you knew yourself that well)

Depending on the details, it may not matter, unless they deal with problematic, dangerous, or otherwise concerning issues that need to be addressed in your personal life.

In fact, uncovering deep aspects of one's self, either consciously or unconsciously are why people practice artistic mediums, and writing in particular.

The Real Question you should be asking, is how will you react when others react to your work?

How will you feel:

If people like it?

If people hate it?

If people critique the hell out of it?

If your praised?

If it needs to be changed?

If others change it?

If others reject it?

What will you do? How will you act?

Will you learn? Will you grow?

Will you get depressed?

It takes a lot of life experience to write what and who you don't know convincingly.

And the more you know, the more authentic your writing could get.

Or

The real issue is you uncovered something that you've been trying to hide for a long time, and you wounder how apparent is it in your writing.

A. If it can be actually traced back to you.

B. If you even realized you put it down in the 1st place.