As others have said, already, sailing upwind feels much faster than it is. Or, sailing off the wind feels slower. There are reasons for this that have nothing to do with how fast the boat is actually moving. Let's say you're sailing in a 10 knot wind. Let's say you are sailing 45 degrees off the wind at 4 knots. That means that you are going 2 kts in the direction of the wind, creating an apparent windspeed of 12 kts. (Not actually because there are other forces at play here, but let's keep it simple.)
So, there you are clipping along with a 12 kt breeze in your face. The wind waves are blowing in more-or-less the opposite direction. Let's say they are moving along at about 6 kts in the direction of the wind. (The actual speed depends on several factors, but again, let's keep it simple.) So, since you are moving 45 degrees to the wind, moving 2 kts in the direction of the wind, that means that you are moving through the waves at 8 knots (the waves, not the water).
So, you have this 12 knot wind blowing through your hair and waves crashing under the hull at about 8 knots. That feels faster than it is. In reality, you are still only moving at 4 kts over the water.
Now, let's turn 90 degrees off the wind so we are sailing 135 degrees off the wind (with a 45 degree tailwind). The feel changes.
Let's imagine that we move at the same speed at this point of sail as we did going upwind - just to illustrate the perception difference. So, we are still moving 4 kts over the water, but on a broad reach. So, instead of making 2 kts in the direction of the wind, we are making 2 kts away from the wind. The apparent wind is therefore 8 kts. (Once again, this isn't what actually happens - it's more complicated, but close enough for the illustration.) Also, the waves are still going along at 6 kts but now we are also moving at 2 kts in that direction, meaning we are running over the waves at an apparent 4 kts.
In both cases, our actual speed is still exactly 4 kts, but the upwind leg feels much faster. The more downwind you point, the more pronounced the effect is.
In fact, if you are sailing DDW or nearly so, in a wind that is in the ballpark of the hull speed of your boat, it will feel as if the wind has stopped and, likely, it won't feel as if you are moving through the water. Yet, if you look closely at the bubbles in the water, you will see that you are moving along at a few knots. Conversely, it is possible to point upwind and feel as if you are clipping along, yet hardly be moving at all. It is important to separate perception from actual movement.
Now, with that said, if you REALLY aren't moving, you might not be trimmed for the conditions. When you are talking about light winds, I'll make an assumption and say you are talking about speeds under maybe 7-8 kts. Most boats should make progress at all points of sail in such winds, if trimmed appropriately. As you get closer to 5 kts or so, some boats really can be hard to keep moving forward. Sometimes this has more to do with simply having enough force on the sails to have them hold shape and position. And it isn't necessarily that the boat won't move, but that it is hard to keep pointed in the direct you want to move with the sails full.
My boat, for example, will sail in such light winds at all points, but I don't like to sail in winds under 10 kts, and pretty much lack the patience when winds get down to 5 kts to sail anything too far from a beam reach. My previous boat (much lighter with more relative sail area) did better in light winds.
Now, your boat should do fine in relatively light winds. You have a good sail area to weight ratio. But, you are sailing quite close to the water, so the apparent effect of wind waves will be particularly pronounced. You could quite easily sail downwind at the same speed as the waves, making it feel as though the wind completely died and that you have stopped even though you may still be moving along just fine.
I used to teach sailing, and the #1 mistake that I saw students make when sailing downwind was to stay sheeted in too tight. When sailing upwind, the effect of sheeting in is that it increases heeling and makes it feel like you are going faster. So, people start to think of the sheet as a sort of "throttle" - sheet in to go faster, sheet out to slow down. Then, when sailing downwind, they are sheeted in too much to begin with. And, feeling like they have slowed way down, they sheet in more to "add some throttle".
A good general rule to get your mind wrapped around it, is to think that your boom is centered with close-hauled, at about 45 degrees to your boat's centerline when on a beam reach, and perpendicular to your boat when sailing DDW. Important: Those are not ACTUAL angles - just broad guidelines to get you in the ball park. In actuality, close hauled has the boom as far upwind as possible, DDW has the boom as far out as it will go, and a beam reach is somewhere in between. (And, what I just said about sailing close-hauled or DDW aren't entirely true all of the time either - just mental guidelines.)
Your boat's fastest point of sail is almost ceratainly very close to a beam reach and it should do well on a broad reach down to 120 degrees off the wind, or so. If that is not what you are experiencing, then it might be a perception issue, as I described, a trim issue, or a bit of both.
