I see you do not have the engine mounted. STOP now and ignore the cowling until you get the engine and prop mounted. I don't think the scribe lines are consistent. If I used mine, my left side would have been cut over 1/4" too short. You may be lucky and you did not cut too far.
With engine installed shim and clamp to align lower cowl to spinner with 1/8-3/16" gap. Use the method for other RV cowls. Mark a line on your fuselage 1" or so back so you can overlap cowl. Support and tape cowl into position and transfer your mark to the cowl. Cut outside the line in increments. Work slowly to get a good fit. If you have already cut too much, just lay cloth to build edge back up to past when needed, cut and repeat.
Scott- 2019 dues paid
Now BasicMed: building a 7A, N579RV at airport doing final assembly, inspection 6 June.
RV-12 N319RV 1st flight 12/2015, now over 300 hours.
Purchased RV-12 sold, RV-9A- 536 hours sold, RV-7 sold, Kitfox sold