thickest paint on the market, its almos like whipped butter.
What is happening is that you are getting different thickness of layers on different areas and the difference is showing.
You do need to concentrate on smaller surfaces and and use the "W" method in a three to four square foot area then move on to the next.
If your painting like a typewriter, going from left to right or vise versa, you can always keep the leading edge of painting wet, but the problem arises when you hit the carriage return and begin a new section on top of the old. This is where you may have paint already dried or close to it. Here, you must feather the new paint over the old to a degree to feather the dry and wet line out.
My friend, Glidden is really good for brush painting, but really difficult with a roller. Its sooo thick.
I would not dilute it down either because this could and will mess up the composition.
You could also just paint it out as your doing, then go over it with another coat after 2 days of drying.
Or you could stop and get another "paint store Brand" paint and begin again.