Your horse will naturally need to be able to lope slowly and properly collected. Without that natural ability, you will struggle and most likely end up with a mechanical, ugly mover.
Sit back, roll your shoulders back. Let your thigh relax, and your lower leg in touch with your horse's sides. Keep your chin up.
If you are able, talk to the owner about the horse's skills. Why have you only been loping it for two months? And as always, my suggestion would be to ride the horse in lessons specific to your goals.