Lying about sex and masturbating

Hi, I have been with my boyfriend for over a year, and for the past 7 months my kids and I have lived with him. I’m getting frustrated because when I ask him if we can have sex, sometimes he tells me no, and makes an excuse...but then he lies in bed next to me on his phone...and says we can do it that night...then that never happens. When I ask him about masturbating, he tells me no he hasn’t...but then tonight he said that it’s been months. So I said, “Oh, so then you HAVE done that since we’ve been together and you lied to me when I asked.” He was quiet...then proceeded to tell me to fuck off and made up some stupid comment about how he couldn’t say years because we’ve only been together for just over a year...but that he’s tired of telling me the same answer and me not believing him...he gets really pissy. Mind you, we are both 40 and I have five kids from a previous 19 year marriage and he has one kid from his then 17 year old gf he knocked up. I just don’t know what to believe and he says he doesn’t have a problem having sex with me, but yet he will go a whole week without meeting my needs and I’m wondering if he’s attending to his needs in another way...I don’t believe him...am I wrong ?