Yacht buyer withdrawing from contract?

My wife and I are in a situation where we are selling our beloved 20m motor sailor. We bought her in Turkey 7yrs ago and have put ALL of our love, blood, sweat and tears into her! We crew her ourselves and maintain her to a high commercial standard, doing absolutely EVERYTHING ourselves.
I am a Kiwi commercial skipper/engineer, my wife is Spanish professional sailor and an electrical engineer, and we have been running our highly successful charter company (just the one boat) in the Balearic islands for 7 years, but have decided to finally put her on the market.
The buyer in question has been keen on her since August last year when he first viewed her but had to sell his Dublin based business before buying her. He has, to date, paid 70% of the agreed asking price with payment instalments going to our highly reputable brokers escrow account. Sea trials and survey reports all done with resounding success and everything looked great....waiting on his official acceptance (his agreement with the broker), the final payment....then we would send all documentation including Bill of Sale to UKSR to simply change names and registration from our commercial to his private and all would be done!
The very official Brokers contract was signed by all parties including the broker late March and states that final payments should have been done by 7th April.... there has been some time allowances for the late survey report etc, and he has been genuinely making deposits and acting 100% as if the boat was already his! Stupid of me to allow this, but he has even been living onboard with his friends for the past 10 days making minor constructional changers for his upcoming crossing!
However tonight he answered my email that I just sent him trying to help him find local mooring options for him here before he departs to take the yacht to Lanzarote. ..... and he has told me he wants to pull out of the deal for no other reason than its all a bit to stressful for him...too many complicated logistics and costs.... yet he owns 2 other yachts!!!
I would like to ask anyone out there if they have experienced anything similar to this and if so where they think I stand legally here? We will talk to the broker first thing in the morning and I truly believe the buyer doesn't have a leg to stand on..... we will obviously try to convince him to continue his course, because failing that, a court case that we would inevitably have would involve claims for a whole bunch of other losses suffered by ourselves, and would eventually cost him much more than the agreed asking price of the boat.
We both held off serious job offers (me as Captain of a new Sunseeker 88yacht, and her Director of a large new marina) until we had signed this contact with the buyer. Not to mention delaying actual repeat client requests for a secured 7 weeks of charters (70K net profit) until we were sure about him buying our boat...we have put so much aside to facilitate him buying our yacht and basically changed our entire professional lifestyle (only upon knowing he was committed) that for him to try and pull out now would be a huge strain on us in every respect! Im very sure that we would annihilate him in court but..... Id like to hear opinions and or other folks experiances if possible.
Any info or advice would be greatly appreciated ... apologies for it being a bit long winded ;-|
Cheers
Black Marlin team

Hi Dockmaster and thanks for your input. Yes the contract is under Dutch Maritime law and has 3 specific articles that quite clearly state the sellers protection in the case of buyer default so I am reasonably confidant that we would be ok if indeed it does end in court. And yes, your shock at my stupidity and over-trusting generosity is shared with most of my friends & colleagues , and is something that I should have known better than to dish out so easily. My faith and trust in humanity is both a curse and a blessing sometimes, however after a delicate, supportive and encouraging email it seems I may have swayed the buyer back on track, and hopefully that his decision to withdraw was more a panicked cry for help and/or a case of cold feet.....so, fingers crossed and I will keep you informed of any further updates in this little saga! Thanks again