Overthinking..

So, I'm definitely an overthinker. I over analyze everything and start unnecessary problems. My boyfriend is not an overthinking and goes with the flow. Sometimes when we fight, I realize how much I was overthinking and started a problem for nothing. I really love being with my boyfriend, but sometimes I feel like I bring him down with how much I overanalyze, not just our relationship; but everything. Is anyone else an overthinking and how do you handle it? How can I stop overthinking? :(