If you want to be an engineer, you're going to have to resolve your issues with math. Almost all of engineering and most of science is based heavily on math. That's probably not what you wanted to hear, but you're only in 6th grade so you have time. If you really want to be an engineer, and have the drive to make it happen, you've got more than enough time to catch up on the math. Do some work over the next few summers and you should be in good shape.
I'd recommend getting to at least calculus by the end of high school. Engineering schools usually require 3-5 semesters of advanced math, and calculus is just the first semester of that. If you're not already prepared for that, you'll need to add another semester or two of remedial classes before you can get to your required classes.
Ability in math and science is definitely required for any career in engineering. A good definition of engineering is applying math and science to solve problems. But the issues you are having now with math do not necessarily mean that you cannot become an engineer, maybe it is just that the type of math you are learning now is not interesting or the way it is taught is not working for you. I can think of several examples where I did not like a math course, but enjoyed the same math when it was taught in engineering college. It helps if the math is taught as part of the process for solving a practical problem, and the way that math is taught in engineering college is different from how it is taught in earlier grades. That said, you have to get through the math courses in school with good enough grades to be accepted into engineering college. Ask your teacher for examples of how the math is used, or ask practicing engineers how they use math in their work. Engineers use math every day. Hand your textbook to an engineer, open it to the page you are studying in class, and very likely that engineer can tell you how that math is used to solve practical problems.
Math is definitely important to being an engineer. However, do not let this discourage you. Understanding principles of math and being able to apply them is what is really important. While the parts of math you may be struggling with now provide a foundation for the higher level principles, in many ways, those are different and you may find them easier or engaging a different part of your brain. There are many 'basic' math skills that I would struggle to do on my own by hand. In my case, I typically build a spreadsheet to handle that type of work.
I would not let the challenges you are seeing now keep you from pursuing your interest in engineering. In fact, they say people who struggle a bit and fight through to learn something, will have a better grasp of it in the end.
You will need math for engineering. I have found that I needed to approach math from a different angle. Teach yourself the beauty of math in that it is in our very existence. Apply math to the every day things that apply to you. Use social media? There is math there, algorithms. Cook? There is math there. Play sports? You get where I am going with this. Apply it to your life and it will embrace you and you will be good at math!
Engineers are problem solvers. The current problem.... your weakness in math. You have the time to hone your math skills. Take this opportunity to explain your desire to be an engineer and get some help from your school/math department. Over the next few years you can see if you can master math. Good luck. We can use more engineers!!!