Advice/Help with Indoor Cactus

Hi is there anyone here who knows how to care for an indoor cactus. I have a Prickly Pear cactus and she isnt looking to good. She is on my window sill in durning the day and I put her under a lamp ( 3 inchs away with a CFL bulb) when the light dosnt go through my window. I usually water her once a week. I got the cactus in the early summer and shes been in the same plastic container, probabley the size of a coffee cup just short and fat. The older part of the cactus has become light brown and lost its structural strenght and needs to be propt up with sticks.

It sounds like it's out grown it's current home. You need a larger pot and fresh soil. That would get ya started in the healthier direction. Get a soil that is designed for Cactus online or at a hardware store.
Those are my thoughts...

hi there windowsils arent the best for catis.just put it somewhere where it gets all day sun and dont worry about the light and also they will fall over top heavy mine fell over when it got to about 6 ft but i had to prop it up with a stick until i put it in the ground and then the stem gets strong enough and big enough to hold its own weight now it is growing like wild fire