I took QFT in college and then grad school in two of the leading institutions in HEP. I can’t say the instruction was very enlightening in either place. Whichever path you take (not sure what you had in the 80s, I’m thinking of Peskin & Schroeder / Schwartz / Weinberg, maybe even supposedly easier textbooks like Nutshell) it’s just a very dense subject.

Now, GR or at least the core of it is a lot easier as long as you’re mathematically prepared for differential geometry.

Btw, I took particle physics from the Peskin in Peskin & Schroeder when I was an undergrad. Everyone in the class (like four of us by the third week?) was super duper lost by midterm.