There is no guarantee really. If you are unlucky, they may not let you enter even with a tourist visa.
You should really do some research and get the appropriate Visa for your long stay. Staying in Thailand for about 6 months/ per year will not be considered as a genuine tourist. If you want to come to Thailand regularly, you definitely need a long term solution.
We don't know your visa history - so it's just a general advice: Do not overstay!
If your stamp history is not too extensive, I would recommend leaving Thailand for a few days and get in touch with the place where you had your ED visa. Let them know that you need the visa to be cancelled, and that you will come next week to pick up the printed confirmation of the cancellation.
Then you could try to get a visa exempt entry into Thailand ( if your passport is eligible) which should give you 60 days.
However, there's is no guarantee that you will be able to enter Thailand again if the IO doesn't see you as a genuine tourist.
Perhaps it would be better for you to look for a company that does a border bounce. They check in advance if you will be able to get back into Thailand.