I've got what sounds like a similar setup- 18 foot "car trailer" with hydraulic floor jack to tilt it. I never use the jack when loading tractors- just drive the tractor up to the trailer, go slowly forward, and the front wheels of the tractor will tilt the trailer. Drive on, slick as a whistle.
My trailer is a "car trailer" type, with bed between the fenders. It probably wouldn't work with a wheels-under-the-bed type trailer- too high.