I live in the Tampa area and can either help to provide an adequate environment, or put you on the right path.
That being said, yourbest bet is to use the CHE (ceramic heat emitter) and put your cham in an open window without the screen, or outside during the day time. Its colder out, thus the need for the heat. The twistee type bulbs are pretty much useless... I have many of them sitting in a drawer.
While you may not be able to afford to buy a linear fixture, your cham can't afford for you not to. I have a cham that had/has MBD and it requires so severe dedication and a complete array of supplements and treatment. I had to add multiple of the "small" fluker branches to her existing vine structure so she could move without falling. Because she's a female, there's HAS to be a way for her to get up and down from her laybin. I also had to provide liquid calcium and LOTS of sun exposure.
While your cham may want to "hide in the shade" when you take it out... that's perfectly fine. UV will still get to it if it's not in direct sunlight... so long as there isn't any glass, plastic, etc. between. Even with our daytime temps being "cold", a simple CHE with something to break the wind and keep the heat in will be more than adequate when it drops below 75ish. In the evenings when it drops down to the 50s, she will be fine and start to slow and go to sleep... but you'll want to bring her in as the sun starts to set anyhow.
All my chams get rotated out to my lanai where I have a good sized bird cage with a few extra basking bulbs/CHEs for this time of year. When my girl had MBD I would hold her near to my body and walk her to the sun. If she didn't want the direct sun, find a chair and sit down. At some point you'll have to get her proper UV. Without the money for a fixture, use the natural UV production of the sun.
I can't offer you a T5 linear light... but I can offer you domes to put incandescent bulbs in (or CHEs if you have them - though the price of one is the same as a T5 fixture...) which will allow you to put her outside for lighting. I also have about 20Lbs of calcium as well as liquid calcium, multivitamins, misc health supplies. I also have a microscope and everything to run a fecal. Also have a bunch of roaches, worms, supplies of various kinds.
Central Florida is a big area... if you happen to be somewhat close by let me know. Otherwise, stick her outside or in an open window. Even a few 10-20 minutes every day will be more than what shes getting now.
If there's absolutely no other options, I've rescued 3 lizards in the past few months.
Best of luck.