Anyone ever break off LTRs for no good reason?

I’ve had a girl around for awhile. She’s a fun girl to hang around, caring, receptive, everything, it’s absolutely no stress at all.

So if it’s no stress why do I still feel the urge to either look too far into things and make up problems in my mind or to cut things off completely?

Am I bipolar or something? I’ll create things out of thin air when things are going completely well.

Thanks.

V/r