I've been overthinking & dwelling on issues that bother me for as long as I can remember, but it wasn't until I started dating recently that it my tendency to overthink & dwell too much become really obvious and has been a source of small arguments here and there (of which some have turned to larger ones). I think if I compare myself now versus say, 6 months ago, I've become better at stopping myself from dwelling on whatever it is that bothers me, which is usually related to the past. Still, there are still so many times when the stuff that bothers me pops up into my head, I can't stop thinking about it even though I know it's only going to hurt me (and possibly my relationship) in the end. I'm pretty sure a lot of this stems from me being more introverted than extroverted and the fact that I was always one to naturally keep a lot to myself even though I've always wanted to easily open myself up to people. What are some ways to stop overthinking/dwelling before it gets too far?