I also recently invested more than I could afford to lose (going from 95% in to 98.5% when price was around $10-11K). Best decision I ever made! This was also on the basis of selling the 3.5% when price broke $18K, as it's actually money I need 
In the end, it will come to how much money you can risk. If you can take the losses if you did the wrong decision then still its ok.Borrowing money to invest in crypto can be a double edge sword as it can give you profit but at the same time it can give you losses depending on your timing. Having a secondary income source to pay your crypto loan would help you too to at least pay your loans. On the other hand, borrowing money is very risky especially if you are just a newbie that you don't know when to enter and exit. Overall, it will depend on how good are you in entering and exiting and how much you can risk.