I am a losing player on the weekends!!!

Since May 14:

Monday-Thursday(the toughest days)
Tables during the week are usually 4-5 regs and 1-2 unkowns(usually bad)

Hands: 84,828
Net: +$9614.3



Saturday & Sunday(the softer days)
Tables during the weekend are usually 1-2 regs and 4-5 unkowns(usually bad)

Hands: 40,033
Net: -$3693.65

I haven't played on Friday during this stretch.

I have played nearly 1/3 of my hands on the weekend and I can't seem to beat the 'unkowns'. I play a very standard Tag game against them, but I consistently lose. I feel that this is a major leak, and I have no idea how to fix it.