Time Capsule backup data disappeared. Rebacking up MacBook Pro. Very very slow

My 1/2T Time capsule filled up and would no longer do backups. I deleted about 30% of the data from my MacBook Pro. Afterwards the Time Capsule backup file appeared empty. I've given up on trying to recover the missing backup data and now I'm trying to start over by doing a full backup. I'm using an Ethernet cable with the WiFi shut off. I've stopped my computer from going to sleep. Progress is painfully slow. After 3 hours the TC had backed up only 210 MB--at that rate it will take over 100 days to do the backup. Any suggestions of how to do the backup at a reasonable rate. I have about 320 GB to backup. Thanks. Larry