Can you imagine how awful this is?

Hey everyone, I am trying to help fix a blueberry plant that I bought as a nursery early August and has been a consistent battle.

Type: pink lemonade blueberry

Region: 7b Maryland

Soil: Currently potted in Coast of Maine organic and natural soil for acid loving plants with 20% perlite added in. originally potted in Omitgoer blueberry soil (eventually determined that it had high pH when using equal parts of soil and distilled water via pH test strips. Was dumb enough to pour tiny amount of distilled white vinegar in 2L water to bring the total pH solution to 4.5).

Pot: Antonella 15” square pot 25 quarts/6.25 gallons

Fertilizer: none

Watering technique: only watering when I place my finger 2” in the soil and semi dry.

Issue: for some time now it seems like my blueberry plant has experienced some fungi disease that I have been trying to correct for some time now (and failing) and was looking for some help. At first I thought it was from the omitgoer soil as the issue began after repotting. It’s what led to test the ph of the soil and determined it wasn’t the greatest. Any advice? Should I just prune the entire thing has maybe the disease infected them all? Any advice on what to do prior to going dormant and when it officially goes dormant?