It also looks like you bleach and color your hair??. Perhaps I overlooked that in your description.
That's some major thick and long hair. Looks luscious
You should really work on getting rid of the damaged hair which means do not look into protein treatments just yet.
If I were you I would consider cutting about 1/8 of an inch from each strand and then only do moisturizing treatments for at least 45 days.
Also, cut out the use of products that have cones during this time so that you are not applying the temporary fix that cones offer. This period will allow you to clarify and work directly with your raw hair so that you can begin to see just how much damage you might have done.
45 days of moisturizing treatments that does not contain cones. Also, I would skip on adding oils until you reach that 45 day mark.