hair breaking off suddenly

Silicone buildup from products can cause breakage to happen suddenly. If you use a lot of silicones (anything in the ingredients of your products that ends in 'cone), and you have been using them for years, they can build up, break off eventually, and break your hair off with it. You should use a clarifying shampoo once every 2 weeks to remove it before it breaks off. It's also possible the anti-residue shampoo removed all your buildup and you did not properly moisturize your hair afterwards? After clarifying, you do need to condition well to put some moisture back in. A good jojoba oil containing conditioner is good for this.

When was your last trim? If you get splits, and you don't remove them, they split much worse. If you want to keep/grow very long hair, it's a good idea to pick through it just trimming off individual splits once in awhile to keep them under control. (If you want to keep it waist length or shorter, this is less of a concern as regular small trims will take care of it enough usually).

another question, are there hair specialists that deal with breakage? If I just go to any stylist I am afraid they might just want to cut off my long hair, but i know the reason cannot be because it is long, i have had long thick hair since i can remember and this week is the first time i have had breakage.

Anything that ends in -cone is a silicone. When you apply these products to dry hair, you get a megadose. Read the ingredients on all your products, including conditioners.

Most silicones can be removed by a rinse of 1/2 cup vinegar in warm water during or before a wash. Some silicones are oil-soluble only. These would be better removed by a homemade heat treatment with oils like jojoba and citrus oil, which is also good for the hair.

They're bad if they cause your problems. I've never had a problem, possibly because I've made sure to clarify my hair with vinegar at least weekly, possibly because the only product I use with silicones is Pantene Pro-V (which other people complain about) that I apply as a last conditioner on pre-conditioned hair.

Clearly, if you're going to have a problem, it will come sooner if you repeatedly apply layers of these to dry hair.

On the plus side, silicones make your hair easy to comb, shiny, and thick feeling. There's no reason not to use them, you just need to manage them appropriately.

The clarifying shampoo isn't necessarily the "reason" you have breakage. To me it sounds more like you were getting breakage from using silicone products for years, but since you never clarified before, the breakage was staying glued in and down with the silicone layer. (If you had stuck with the silicones and never clarified, the breakage likely would have caught up with you eventually anyway).

p.s. There are long hair stylists like Louise Marie Longhairs (in Canada I believe) and George Michael salons (neither of which I have ever been to). Those would probably be safe to visit if you want to keep all your hair, but any others will probably just want to give you the standard trim.