First of all, heres the picture of one part of the trees leaves
Now, i bought this pyracantha from nursery stock about 2 months ago at the end of june. I repotted it then in a very large pot to let the trunk grow. It went through alittle shock then produced some new growth and was doing fine. A few weeks ago the leaves started changing to this(the picture). I posted about a week ago and i was told it was just going through shock, but now its 2 months from when i repotted. I've been watering lightly everyday(i think pyracantha liked the soil moist all the time
).You can see some small bright green leaves at the end of the shoot that have just grow, so its still producing but more leaves are starting to die like this.
Im thinking this might be root rot because i had a smaller pryacantha whose leaves looked exactly the same and eventually died.
In the case that it is root rot what should i do? Is it to late?