Gulf coast 50x50 front lawn . 5 years ago landscaper sc****d,graded planted tree, ornamentals ,in 10" new top soil. Remainder new st Augustine sod. With irrigation.every year winterized and in spring weed and feed. Last year did not winterize and did not weed and feed. April noticed lawn turning brown. Increased watering. Week or 2 looked greener but different . Careful inspection ,new green a vine like growth . Advised it was button weed. Waited for a cool day and treated with fertilome weed b gone by directions 2 tbs per gal. Destroyed most of my lawn. Advised too strong. Have been pulling B/W as appears . Treated again after 6 weeks , 1/2 strength 1 tbs per gal. B/W shows darkening but comes back. Have stopped watering , letting every thing else grow , to compete with B/W .....Have been pulling every day. Killing my back. I'm on the ropes. There must be a better way. Please. Desperate. Advise, if you can.