Help please!!

So my husband is 36 and we have been married 3yrs. We have only ever had sex about once a month even while dating. I try everything I can think of to turn him on, lingerie, subtle advances, blatantly telling him I want/need sex. He turns me does all the time. Then when we do have have he lasts 2 minutes at most. I'm at the end of my rope. I love him but we have zero sex and zero intimacy. How do I fix ot or make it better???