It depends on what your toilet supply lines are like and if you use a cold water only or a cold/hot water bidet, but a cold water only one (not nearly as uncomfortable as imagined before trying it) is very easy to install as long as your supply line has a shutoff valve and is relatively flexible.

It takes 15-20 minutes and it basically consists of unscrewing a few things and screwing them back together again.

I would second this. I read most of "No More Mr Nice Guy", and while I found it helpful in some ways it also was just not as "clean" in my opinion as "Boundaries" by Anne Katherine.

I have difficult times in relationships also, and your post sounds similar to things I've struggled with - general personality / demeanor acquiesce with uncertainty or internal disagreement, very flexible most of the time until very stubborn in certain ways, not feeling like I can recover my peace & internal clarity before another wave.

I recently read the book Boundaries by Anne Katherine (https://www.amazon.com/Boundaries-Where-Begin-Recognize-Heal...) and feel like it was exceptionally eye opening. I always felt like I had a normal-ish upbringing (but how do you ever really know, outside of egregious abuse?) but there was very little to no modeling of positive boundaries and individuation, and it has negatively impacted my relationships.

I've also read some of Henry Cloud's "Boundaries" book, but it was a little too Bible-oriented for me, but that may not bother you. His writing is very clear and he had many insightful gems sprinkled throughout the heavy reference to scripture.

It also may be worth talking to a therapist or counselor (and I would suggest doing it just for yourself first) before trying marriage / couples counseling. In my experience with marriage counselors (admittedly not a lot), the relationship itself is effectively the client. The one I went to wouldn't even discuss with us that our marriage may not be right for either of us whereas a personal therapist is there specifically for you.

Thanks for your detailed reply. These are all good points. I need constant reminders about perfectionism and I like that quote.

Thank you, I will check those out.