Your plant's leaves could be turning brown for a number of reasons and is probably stressed. Blueberries prefer well drained soil and a sunny location. While most plants prefer a more neutral pH, blueberries prefer a more acidic soil with a pH level of around 4-5. Because of this, it is good to fertilize them with an acid fertilizer (rhododendron or azalea fertilizers work as well as organic blood meal or cottonseed meal). It is important not to over fertilize as blueberries are very sensitive to too much fertilizer.
I think you could not feed the fertilizer properly to your blueberry plant. If you want to rejuvenate your plant, then you should take care of properly and feed organic fertilizer for blueberry. Every fertilizer pack gave the instruction, follow them which they instruct. I am using the Winchester Gardens fertilizer to my berries and feed water every day at the same time.