have a lot of errors on my website

1. The "ADD" button in the Field-bound Boxes it's invisible
2. The Testimonials display the error message
3. Multifield Location Filter the "Add an Entry " button invisible
4. The "ADD" button of the listings box it's invisible
5. MySQL ERROR when creating a new user account by admin or super admin
I don't know why.
6. Payment gateway When I use the test mode to check out, it only displays a loading message for a long time

I don't know how these problems arise. Even though I didn't edit or write any code because I don't have a coding knowledge,
But there has been a dramatic shift on my website. And it greatly affected my website settings. I'm extremely worried. And I'm afraid these problems will happen again when my customers use the website.

2 days ago I had a problem with the limited admin access Flynax support helped me to fix it, but after that what functions about the item box that I give to limited admin, it's can not be used by another admin including the super admin because the "ADD" button it's invisible only limited admin that I give permission (anchalita) can use it, I create a new admin and give the same permission but all admin can't use it.

I sent the ticket already but no one answered me

I am really worried about these issues because I have almost finished setting things up on my website. But found a lot of problems. And I don't know how to fix it. This website is my dream and everything in my life. I am very impressed with Flynax's script and plan to purchase another mobile application after I finish setting up my website. Right now I have cancer and I don't have much time left to create this website as a business for my wife and children and my family after I die.