Cardio vs strength training?

Ok so here is my dilemma I have lost 4 pounds in three weeks but now of course I have stopped losing weight I have gone a whole week without losing weight when before I was losing 1 � a week by the way I am on weight watchers I also take kickboxing 4-5 times a week. I want to continue to lose more weight and I only have 6 more pounds to go so I have no idea whether I should increase my cardio or my strength training. In the kickboxing cl we do 20-25 minutes of strength training and 20 minutes of cardio and I have been doing it for four years but on and off so I actually recently went back to it in aril I am so confused I am being told that after 8 weeks your body gets used to whatever work out you are doing so you have to change it. So what I need to know is should I be increasing my cardio or strength training and should I try a different workout now? I was told if you want to lose weight by your close increase strength training if want to lose weight by the scale increase cardio. So please someone out there help me. By the way I do eat right so its defently not my eating I am sure of it. if I increase strength training is that too much then because I already do 20 minutes of it in cl I really need detailed advice. I was thinking of starting the abs diet help