Good. We have a problem. What's the solution? Step feeling? Stop thinking? Stop wondering? Or are you suggesting that when we're thinking and feeling, that we just keep that to ourselves because that's the healthy thing to do?

To stop thinking via processes that deliver hurt. "Assumptions" and speculation", for instance, are based on what? They're guesses, conjecture, based on interpretation, which means they're filtered through a bias. Then dwelling on those assumptions creates further assumptions, but meanwhile delivering misery. Only to find out later that, sigh of relief, it wasn't what you thought in the first place.

Instead, change the way one is dealing with these thoughts to a more practical, beneficial, healthier mode. You'll find that feelings follow thoughts, and if the processes in the thinking involved are healthier, so will the feelings be too.

In fact, your statement reflects "all or nothing" thinking, which is another distortive reasoning process, though right now your perception of your statement is that of honestly asking a question, which you are, but which is processed through that type of reasoning nonetheless. I'm not being critical of you by writing this, I'm addressing the process used instead. Your statement gives the option to "not making assumptions or speculating" as leaving only "What then? Stop thinking completely", when it's not one or the other.

There's a book called "Feeling Good" that delves into this topic in detail which I'd recommend to anyone.