Dealing with Relationship Anxiety

me and my amazing bc have been together for a little over 6 months now. we are both at the age where we both are “prepping for adult world” (him at 21 me at 19). due to this and him being a little older than me, he’s really busy lately. he is always so reassuring and just amazing that sometimes what used to get to me doesn’t anymore. but now that he’s busier i’m anxious all day every day thinking he’s being distant from ME and not that he just has a lot going on. it’s leading me to constantly communicate irrational thoughts, and then realize they’re irrational 5 mins later; which confuses us both. how do i be more mindful and keep those irrational and intrusive thoughts away so i can just support him during this time in his life-not cause him extra stress