Hello, I Am An 18 Year Old Male, 6 Feet

Hello,
I am an 18 year old male, 6 feet in height, weighing 175 lbs, who began consuming marijuana by inhalation (smoking) in October 2017, and ceased this activity by August 2018. I have smoked roughly 3 to 4 grams of marijuana over this 10 month period. I also consumed alcohol along with marijuana on three separate occasions. I consumed these 3-4 grams over the course of roughly 20 sessions of smoking, with about 10 sessions involving heavier usage and 10 sessions involving light to negligible usage. While I have recovered from the short term effects of cannabis, I am worried that I may have harmed my intellect, thought process, and overall ability to learn in what may be a measurable IQ drop. Can you either confirm this suspicion or put my mind at ease? No existing credible studies support a reliable conclusion as to what I may have done to my brain.