Every 15-20k miles for a big fuel filter like that? Thats once a year! I think that change interval is meant for for those little tiny inline fuel filters on old carberated engines... The 7th gen civic doesn't even have a replaceable filter, just the sock on the pickup tube. I have a similar sized fuel filter on my other car, i changed it once soon after i bought it and that one had about 140k miles on it and i could blow through it not too bad. I changed it again when i was having idling issues 125k miles later and i could blow through that easy. Made no difference to change it. I gas up at the cheapest places, have put gas in from farm storage tanks, year old gas from gerry cans in, run the tank dry several times...
I think the OP should for sure change the filter, always change it when you have problems, its easy, but i dont think you need to do it every 6months or every year is all. If changing the filter helps then cut it apart. Look to see if its rust or if its dirt. If your gas tank is rusted out and plugging the filter you could go through a pile of filters quickly, easier to change the tank or even just flush it then.