My boyfriend says " FU#*" YOU" to me a lot -- am I being irrational for leaving him on this basis?

we've been together a long time... actually 14 years, but the profanity is new and the intimacy is over. we don't have any kids ... he says I'm being weak and immature by leaving him. But I'm tired of the F word and being called a B. Do other relationships go through this? Is this normal? I'm not sure cause i've been with this guy forever