Apart from Sun and Moon all planets spend some time retrograde - when the appear to be moving backwards through the zodiac. The mechanics of this depend on the relative speed of Earth and the other planet in their orbits around the Sun'
Traditionally, moving in the wrong direction was seen as being a debility, or weakness. Now that's just one weakness out of a balance of strength and weaknesses and taking it on its own is dangerous and often misleading - rather like saying that Superman is allergic to Kryptonite so he must be a weakling compared to humans, who have no such reaction
Jupiter is usually associated with good fortune and good luck. Being retrograde does not suddenly make it unlucky or rob it of that quality. It's still fortunate but on that ONE measure, it's less fortunate. Your Jupiter is also in Aries, a fire sign, so it's in its own triplicity (element) which makes is a strength, it is conjunct an angle (the IC). which also makes it stronger.
One indicator is not enough to change the entire meaning of a planet and indeed a whole series of debilities would not make Jupiter unlucky but it could make Jupiter a lot less effective in bringing luck or fortune.
Incidentally, I've often found that people make their own luck and 'hard work' can bring much more fortune than sitting back and waiting for things to fall into your lap. Your Jupiter can and will be effective, it does not in any way preclude any luck because its retrograde.
One last thing, your post focussed on the 'luck' or 'fortune' side of Jupiter, it is also the planet of expansion and growth and your personal growth is in not removed by Jupiter being retrograde for exactly the same reasons.