Go with your gut. If you are ready to end it then do it! 21 days is a huge accomplishment! I have read articles on evoo regarding how it affects greens positively. They say that when you use it on your salad you are absorbing more of the nutrients from the greens than you would with no oil at all. Google this and you can find articles on this. That being said... I don't always use it but when I do I just use a small amount. Here is the issue about how soon to eat fish or chicken. I don't eat chicken but I do eat fish. Everyone one is different. I can tell you I eat solids right away and have never had a problem or gotten sick. I'll eat a raw zucchini pasta tomorrow night which is my first day off. I am NOT encouraging or advocating this for anyone else! I'm just saying I am able to do it with no stomach discomfort in the least. But you may be different. You can try a small portion of something and stop and wait to see how it affects you if you decide you want something more substantial. I don't eat meat or dairy so I'm certain that helps. I do strictly veggies and some seafood.
It sounds like you have a great game plan for your future food choices! That's the mindset to be in coming off of it and beyond. I'm easing off tomorrow too! Only one more swf to go!!