How to spend my lottery win carefully?

Look at it rationally, logically, financially and most importantly, CALMLY. If you have debt(s) and can pay them off and still have a good portion of the winning left over, do it first. If not, pay off some of the debt(s) and allocate a portion of the money for your other projects. You have to do what's right for you first. If you can save some of it too, that's icing on the cake. Also, pay yourself first. You need pocket money right? Take a 10%-30% spot for yourself.