I don't know what the basis of G.C.'s staement was, but if it was some "test", let me explain how they bascally work.
Questions are adminstered to person various fields to develop the "Norms" or avarages;typically the question require endorsing some statement like, "Do you like fishing ?" If you score a profile "similar" to thew Norms, well, you must be the type for that. Huh?
Females have been historically been told they are not "good" at "male fields".
Guidance Counselors in H.S. in USA typically are the "administrative assistants" to Principle. Rarely are they selected for clinical acumen but usefulness and friendliness to Principle.. In fact, IF they have a GC degree, it is almost entirely lacking in clinical training. Often they are teachers "acting" as Counselors.
Now don't let me start a Flame here with all the Good Guidance Counselors around. Just talking err..."norms".
The only way to find out if you are "good" in math and science is to take math and science courses, preferably with decent teachers.
"The proof of the pudding...etc."
I think I wrote this once before: It is a great error to pick a career based on a single test or a single person's opinion.
OK, like most of us you have found yourself in a situation: the philosopher Heiddegger (hate to quote him

) called "throwness". You simply have to work your way out of whatever jam you are in now.
Look at the job market, your present interests [see below], actual working conditions (not the same thing as the "field" ) and how you are going to get training aka support yourself while retraining.
There are ancillary medical fields like Dental Hygeinist, EMT, radiological tecnician, MRI technician which don't require a quarter century of training--maybe 6 months to a year. (CK the foregoing--maybe wrong on some) but you get the idea. (Many can be done Part time. Didn't notice where you live.)
Keep an open mind. and be careful what you wish for: you might get it !
By the way; know several people perfectly content to do some job that brings in the moolah, while pursuing their "real" interests on the side; e.g. a chef who records his own music. Hence, consider "top dollar" jobs as an alternative.
DOOOOOG