Unless you can find a way to re-hang your light so you can gain a little space you may be impregnated.
　
I have run into a similar situation in the past and with a little creative thinking I was able to gain a small amount of height to use. For one what sort of ceiling is above your plants? Is it suspended ceiling? If so you may be able to remove a ceiling tile or two and re-hang your light above where the ceiling now is and let the plant grow through the opening.
　
Something else that is not great but might work is to take a piece of stout wire or maybe a coat hanger and bend it and attach it to your plant stem with a zip-tie or plant tape. Bend it so you can tie down the soft new growth and make it grow like say 6 inches to one side and then make the next bend so the new growth can grow up an inch or maybe two and then make another bend so the new growth can be tied down and grow back the other way say a foot (to keep things more balanced) and then bend to go up another inch or two and then back the other way a foot and so on and so on. Or you can bend something into a circular pattern that goes up but slowly and again keep tying down the new growth.
　
If you already have a top cola forming that will not work because they tend to not bend well and do not care to be bent but if you are still getting only soft new growth you may be able to do the above and keep the plant low enough so when the top cola forms it then still has room to grow.
　
Something else I have seen pictures of people in similar situations do, though I cannot swear it is good or that I would try it, is to again bend some stout wire, like a coat hanger, into something like a shallow ‘V’ shape and then at different levels along the main stem attach the bent wire and then bend the stem so it can then be tied/taped/zip-tied to the bent ‘V’ shape wire. It will crimp the main stem some but according to the claims I have read a mild crimping will not do enough damage to worry about and certainly not be worse that cooking your top or cutting off what should become your main cola. You do the same thing several times at different levels and each time you regain a small amount of height by having shortened the plant.
　
Other than being able to raise the light somehow, like through a suspended ceiling or finding a way to shorten the hanging device/chains or whatever, I really do not care for any of the other options myself but desperate times call for desperate measures.
　
The only other thing I can think of is if you can re-hang your light, and hopefully add another one, so they hang vertically and shine from the side into your plants. That would then give you the full height of your grow area to use.
　
If none of those are a viable option, not to sound like a pessimist, I do believe you are in this case impregnated.
