I share the sentiments of those above but, to actually try to answer your question . . .
It's not clear as to whether each of you is currently living with your own parents or whether you're both living with one person's parents. That might make a difference as, if you're still living apart, lenders might not see you finances as linked. (So the possibility of applying for two separate loans could be considered).
However the fact that you've already applied for a joint loan is likely to show up on your credit record, so your finances will be seen as linked (meaning that two separate loan applications would be seen as one, and possibly treated with greater hostility if lenders think that you're trying to cheat the system). Further, if you tell lenders that part of the reason you're seeking a loan is to pay for your wedding, then your finances will automatically be linked together (even if they weren't before).
It's probably time to
(a) accept that you're not going to get such a big loan (which is evidenced by the fact that you've already been turned down) ; and
(b) reassess your priorities (perhaps by looking to save the deposit on a flat and then take out a loan,in the form of a mortgage, which is backed by bricks and mortar).