These are the yellowing leaves. Thanks in advance :)

It's a Meyer, so it is sensitive to light changes; when you make a significant light change, it responds by dropping leaves to replace them with new leaves better suited to the new light conditions. Your tree is also suffering from transplant shock; and sad to say now, but the MG citrus soil is not very good for your tree; and the fertilizer spikes do not give the tree what it needs. I probably would not change the soil again now; but plan to do it later in the Summer when you have had lots of new growth. You don't say where you live, or if the tree will remain in a container or be planted in the ground. Get a good citrus fertilizer and start feeding your tree as per label instructions. There is a mountain of good advice on this site about soil and fertilizer.
As for the flowers, leave them until the flowers are gone; and then remove most if not all of any BB to pea sized fruit that has set; you should get a flush of new leaves and branches shortly thereafter; if the tree is stressed and you remove the flowers, it will only make more, using energy it needs to make new growth.

Ok great! Thanks johnmerr!

I live in south Louisiana and would like to keep it in a container but am not opposed to planting in the ground. I have plenty of yard space to plant it, but I kind of liked the idea of it being on my patio and not growing too big. If planting it in the ground would be better then that's what I'll do. Should I wait til the fall to plant her?

I will definitely get some citrus fertilizer right away.

My Meyer lemon is covered in blooms. New leaves usually come later. If to many lemons develop they won't turn yellow. You will have to take some off if that happens. Lawst year the citrus leaf minors did a lot of damage to it. This week I released 1500 ladybugs in the yard. We will see what they do. My tree is about ten years old and I got two dozen lemons last year. Citrus trees don't always grow fast but last year wasn/t a good year. I hope this year will be better.

They do better in the ground.

Kalyn,
I would definitely plant it in the ground; Meyers have a deserved reputation for being "finicky" in containers; but in the ground they are quite docile. I would move it now to the place you are going to plant it, so that it will adjust to the light there. Leave it in the bag until you get the new growth; and then very gently put it in the ground.

Great advice and thank you all so much!!!! I have a spot near my garden that will be perfect and I can easily add a line for irrigation! I really appreciate all of your help!

Jtafaro I've been wanting to do something to attract lady bugs but haven't had the time to look into it! Besides being so beneficial to so many plants, I just love the little critters :)