You need to get some of the basics probably starting with the grip, and turn your body/hips/feet way further back from your throwing stance so you start from a closed position. It's going to feel like your are throwing almost backward, that will help you keep the disc on a straighter pull line toward the target. Slow down the beginning of the throw and finish fast into the followthrough. I'd recommend not keeping the off hand on the disc in the backswing, and let the arm swing back from the hip turning back.
Pretty much any pro tip video will help at this point, the Stickies have a ton of great info: viewforum.php?f=2
Your arm moves around you in an arc. The arm should move in a straight line. That is helped by moving the body from the reach back to the rip point in two different stages. The first one is moving with the steps mostly until the disc is at the left side. Then moving the arm mostly getting it to the right pec area during which time the legs and body turns very slowly or not at all pointing the knees and the navel 90 degrees left of the front of the tee. From there the right pec drill. Search for it on this site. Basically getting the elbow forward of the body is the first step in developing snap. You were leading with the right side not the right elbow.
Flat shots need running on the center line of the tee and planting each step on the center line. Anhyzer needs running from rear right to front left with the plant step hitting the ground to the left of the line you're running on. Hyzer is the mirror of that.