XL endorsement is pointless with 300 hours. Insurance companies won't touch you till the 750-1000 hour mark. Skydiving flying is demanding enough starting out on piston singles, let alone on a complex turbine. Try and find a DZ that has one or more aircraft that you can actually fly with your hours (182, 206 and Airvan being the most common ones).
And AFF isn't necessarily a requirement for meat bombing, if you go talk to a DZ operator with the right attitude they'll let you hang around and help out. I'd never jumped when I started as a jump pilot.