Ouch - heres wishing you a quick recovery!
Attaching the doors to the tarp would be an easy task. A few weeks ago I hadn't ever touched a sewing machine in my life. My 1st project was a down UQ, followed by a hammock, stuffsack, ridgeline organizer and bugnet. Ramblinrev's videos are great for beginners if you haven't seen them yet. Gives great instructions on different types of hems and use of grosgrain. sclittlefields DIY guides are also helpful. Love to see pics when you're done.