Replying to 3 and 5 help

ive searched for help wit 3s and found the stuff about looking with ur head and bringing ur knees up and shittt. i always get around 270 and then stop spinning even with a pre windup and lookin over the shoulder. and its a littl scary once u get past 180 i think thats why i dont make it all the way around. any tips? also the park is shit rite now and theyve got 2 about 30-40 footers and a few 5-10 footers. ive been trying 3s on the small ones and make some even 5s but then some days i jus stop spinning. should i try the bigger jump i dont want to fuck myself up but i want to learn 3s and 5s well.