AA5BY is likely right, but I'm also going to suggest measuring the incidence before doing anything. Having a set of hard numbers to work with lets you really know what the problem is and lets you put it back exactly as it was if your adjustment doesn't help. It also lets you make fewer adjustments as you can get a feel for how much difference a given change makes. If the budget doesn't allow for buying an incidence meter now, you can mark the center line of your airfoil forward and aft and use a ruler to measure the difference. Then divide your chord by 360 to find out how much difference in height a degree makes, and divide that number into your measurement to get the incidence.

So for example, if your chord is 7 inches and you measure a 3/32 difference in height, you'd start with 7/360 which gives you .019444. 3/32 as a decimal is .09375. .09375/.019444 is 4.82 degrees of incidence. To do this right, you have to block the fuselage so that it cannot move at all, and do your measurements on the exact center line of the airfoil. Leave the marks you make until you're done with adjusting so you get accurate measures of the changes you make. Things can be complicated a bit by the movable control surface on the stab, so you have two choices to handle that. You can clamp a straightedge on the elevator, always in the same place, and measure at the back, or you can measure the thickness at the trailing edge in front of the elevator and make your measurements at the top then adjust for the thickness. So doing it that way, if your stab is 1/4 inch thick at the TE and you measure from the top, you'll add 1/8 inch to your measurement to be at the center.

Of course option 2 is to buy an incidence meter and attach it to the surface, then read the dial to get your incidence!