Having that trouble raising the main sail could be obstruction in the mast or the mast is prebent to the wrong shape for the sail, to make sure there is nothing in the sail track I use a scouring pad bent in half so that when you insert the bulging bent bit in the mast track like a sail it won't pull out and then I scour the inside of the track and you can feel if there's any obstruction. If you lay your mast on the ground then stretch your sail out on the mast but not in the sail track, you may find that the shapes don't suit each other so you can adjust your spreader arm settings to suit.