should i tie down

hi, i have a 7week old plant in a 2 gallon pot, it is very very bushy and some of the new growth in by the stem i think is not getting enough light because it is really bright green and the leaves look burnt and under devoleped not sure whats going on, i have 6 6500k cfl's and 2 2700k cfl's on one chocolate chunck plant, had a nitrogen diff, but i feed it and is not changing, it is in 12/12 lighting now. can anybody help, this is my first plant and is 2 feet tall..