Nymphs snagging on bottom

Hey everyone,

Was out on the water today and no visible bugs, so decided to put on some nymphs (Frenchies, walts worms) and try my luck. Unfortunately my nymphs kept getting snagged on the bottom, either in the rocks or mud. I lost several. I was fishing with an indicator, about a 7.5 ft leader and 2 feet of tippet. I tried moving the indicator closer to the fly but it kept sliding around each cast.

Any tips for keeping nymphs off the bottom?