Am I wrong to be frustrated with my boyfriend?

My bf & I live together. We've been together 2.5 yrs & have lived together for 2 yrs. We recently bought a house together. (Please don't preach to me about that). Things have been perfect until recently. Now almost all romance has stopped (I know we are busier & have less $) on his end & we've talked about it ... he genuinely apologizes & says he will make sure to do things (then he doesn't). And then his friend (who he works with) moved to the same town & now the 2 are inseperable, they have to see each other almost every evening. Since he has been hanging out with this friend, he has become a pack a day smoker &has stayed out all night without calling a few times. I feel that he would rather hang out with this guy in his free time (he sees him at work) than me. I can't help but feel somewhat resentful of this friend since his arrival our relationship has changed & we fight. What to do? Sick of arguing, love him so much, know he loves me. I think I am being taken for granted. Advice?