What distinguishes loss aversion from risk aversion is that the utility of a monetary payoff depends on what was previously experienced or was expected to happen.
Loss aversion is most times a product of getting your fingers burnt from previous experiences. Or knowing someone who has.
Sunk cost fallacy is a phenomenon where somebody justifies an increased investment of money or other resources based on the cumulative prior investment (the sunk costs), despite new evidence suggesting that the cost of continuing now outweighs the expected benefit.