Q.Jasmine plant not thriving , leaves going pale yellow
My potted Jasmine plant was not thriving, stunted growth,no flowers, and so I began fertilizing it weekly with a phosphorus heavy fertilizer on advice from a friend. Then, after 3 wks of this, I started to notice some yellowing of the leaves. I bought a PH testing kit and saw that the soil was very high alkaline (8) and so I read up and went out to buy some soil acidifier. The soil was also reading as extremely dry and so I gave it a good watering. A couple of days later and the yellowing has sped up significantly, to the point that many of the leaves are almost white. The white starts in the veins and then consumes the leaves from the inside to the outside.
Plant is potted, lives in a full sun area on a back patio. Summer here has wild swings in temperature (50 at night, 90s during day) but it is very dry here.
I’m worried I’m going to lose my plant and that I’m doing all the wrong things. Total brown thumb person here. Please help!

Certified GKH Gardening Expert
This article addresses the possibilities for the problem you're having: https://www.gardeningknowhow.com/ornamental/flowers/jasmine/jasmine-leaves-turning-yellow.htm