so my girth is only 4.6 inches and I always see how girls want a thick dick. So what can i do to make her stay with me because I have a feeling she’ll leave me for a guy that’s much thicker down there
Give her awesome oral and give her orgasms. I wouldn't worry about your size. Most women aren't really that vain or focused on the penis only with a guy.
I'm not small, but my cock is not nearly as thick as the thickest my wife has enjoyed. It makes no difference at all. With great foreplay, oral stimulation, use of toys and other techniques that she enjoys, she has great orgasms, much better than the ones with the big thick cock.
While my length is average at 5 1/2 to 6”. Circumference is 6”, my thumb and forefinger can barely touch when gripping it when erect. My experience is that technique is more important than size. Having said that, with the correct technique I get comments that the girth is enjoyable.
Wow. If there is no exaggeration here (and I suspect there might be), I've been moving in the wrong circles. But I must admit I've never pulled out a measuring device at that time.