Is there anything that i can do to help him last longer or get him to stay hard after?

Every time me and my boyfriend have sex, it lasts for about 2-5 minutes at most before he finishes. He use to be able to get hard right after so that we could go again but now he can't. It is really frustrating because I never get to finish and I am sick of having to do it my self but there seems to be nothing that he can do to help, fingers and tongue and stuff just don't do it for me. I am wondering if there is anything that I can do to help him last longer or get him to stay hard after it so that we can keep going (I have tried all the arousal things to get him hard but it just goes limp as soon as it gets hard). I know that he is frustrated with it and I hate that it bugs him so much. And I would really just love to have a good round of sex with him because I know he wants it and I want it. We have been together for a year and have been having sex for 11 months of it and we have yet to make it last long enough. I also hate it because I get so excited and horny then I get nothing in the end. He has had girls dump him before for this problem and i would never do that but it makes him a little insecure about it. Please help me!