No good sex

So ladies i need some advise my wife and i have been together for 7 years and lately sex has not been all that i asked her whats wrong she told me she don't feel me anymore i asked explain she said she don't feel my penis anymore haven'tfor awhile i asked what can i do she said she dont know and that why she haven't been getting excited with me any advice? Oh i am 6.2inches big.