Do you at heart feel that you have been thoroughly investigated enough as a couple?. From what you've written about the tests some have been missed out. Have they ever assessed you to see if there are any auto immune problems or clotting problems?. Have they been thorough enough with his semen analyses (plural as one is by no means conclusive).
The most common tests that tend to be omitted are:-
Adequate x-rays of the uterus which may show abnormalities not otherwise seen at laparoscopy.
Hysteroscopy - telescope inspection of the inside of the uterus which may occasionally show abnormalities not seen otherwise
Repeated sperm counts over several weeks and months to make sure there is no subtle abnormality
Testing the sperm in special media such as swim up tests like velocity testing. However, when they are done, they often uncover a hidden cause for the supposed unexplained problem
Thorough hormone tests to detect abnormalities of male hormone or early falls in progesterone
Scanning of the ovaries to see if follicles really are developing and there are no sign of polycystic ovaries.
Unexplained is not a diagnosis at all; what this means is that they have failed to find out what is wrong. Its often given to couples when they as a couple have not been adequately investigated as well.
Any test result over 6 months old should be discounted; you both need up to date test results. My guess too is that you have not had all the tests done either and are in this limbo.
You need to go back to the GP and ask to be re-referred to another subfertility unit preferably in a large city. It is fair to say that in the NHS at least some of them are far better than others. The people you have previously seen seem to have just written you off.