Leaves are dark green light green and brown spots

Looks like lockout based on what i see in diary weeks. Early on you weren't watering entirity of pot.. almost certainly got buildup from then on, if that habit continued for any period of time. Also, leads me to suspect youdidnt get ~10% runoff very often. you want a higher pH in soil. slightly acidic ~6.8pH This may help on its own. make sure to follow wet-dry cycle. only water/fertilize when pot is light and top 1" is dry. Ensuer entirity gets saturated, so some runoff is inevitable. When you fertilize full strength you want at least 10% runoff. throw it out, throw it on the lawn, but don't let your pot sit in it.