Selling before buying

Hi all,
We are currently selling in inner northern Melbourne. Market is slow, been 2 weeks and nothing, anyway.. waiting for an offer to arise then to become unconditional, is this “safe” enough to be able to make an offer on a new house ( we have enough for the deposit for the new house)
I’m constantly thinking of all the worst case scenarios etc but my conveyancer and REA have assured me that once it becomes unconditional it’s set in stone and they have honestly not seen a settlement occur. Meanwhile my negative thoughts like “ what if the purchaser dies” creep in .
The other option is to totally wait until settlement happens and have to rent or air bnb, I’ve been looking and some are like 4.5k for a month and that’s cheap.. I would rather spend that money on the new house..
anyway help !