Not sure I qualify as a hair color pro, but I'll give it a shot since I've been coloring my hair for almost 40 years and have been blonde, red (disaster) and all shades of brown.

Yes, definitely go to a salon next time because you are having trouble. The best advice I can give is not to dye the whole head. If you must dye the whole head, make a commitment only to dye the roots as they come in after that. You can't keep dying all your hair over and over - it is just too damaging.

Before you go in for your next dye job, use a heavy duty protein treatment. You can get it at any drugstore. I think one is called EmergenCee. Follow that (in the same shower) with a heavy duty conditioning treatment. Just plan to spend at least an hour between these two treatments. Boring, I know, but it will help.

Also, if you are bound and determined to have hair that is wildly different from your natural color and requires a stripping dye job, consider a wig instead. I'm serious. Most brown and dark brown hair has to be stripped to become blonde or have that blonde ombre effect. A professional is what you need.

Good luck going forward with this!
2/c and some 3A.
Protein sensitive but can use occasionally
Highly porous. Color over grey.
Best 1st day method: Super Soaker
Stylers: Mix Curls in a Bottle into everything for shine. Terrible pj
Sometimes try roller sets - classic glamor but I prefer my curls.
Every day is a gift