The only way to improve your sGPA (2.42) is to ace your BCMP classes. (Engineering courses are NOT included in sGPA calculations.) You need 52 BCMP credits (or 13 classes) with As to raise your sGPA to 3.5. I’m not sure it’s possible for you to raise your sGPA to that level before you graduate from college.
I strongly suggest that you put pre-med aside for now and concentrate on improving your academics. Drop your pre-med ECs and use the extra time for your schoolwork.
Your first order of business is to figure why you’re struggling in your science & math classes:
Did you effectively utilize the resources available to you? Tutoring? (Both thru the academic support center or a private tutor.) Office hours? Study groups? Did you do extra problem sets from different textbooks? Use Khan Academy you tube tutorials? How about 3-d model kits for ochem?
One last question–are you sure that BME is the right major for you? It appears that math/science is not your strong suit.
Ouch! The B- retake on Ochem is going to hurt you big time. Adcomms expect to see As for retaken classes. It’ll be a big ding on your application. (Med school admission is a negative process. Adcomms are actively looking for reasons to dismiss an application so you want as few dings as possible.) The B for Calc 4 isn’t helping your case either- even though calc 4 isn’t a med school pre-req. It just confirms that you’re not a strong student in the adcomms’ eyes.
I don’t know where you heard this but it’s not true. At all. Tough majors (engineering, math, physics, etc) do not get and slack w/r/t GPA when it comes to medical school admissions. They are expected to have the same strong grades as everyone else. BTW, “tough” majors are in the eye of the beholder. (Meaning some people find foreign languages very difficult or writing/reading intensive majors like English lit or history or theology.)
[MCAT and GPAs for Applicants and Matriculants to U.S. Medical Schools by Primary Undergraduate Major, 2017-2018](https://www.aamc.org/download/321496/data/factstablea17.pdf)
Mean sGPA and GPA for med school matriculants by major—
Physical science majors – sGPA 3.69 and GPA 3.72
Math & stats-- sGPA 3.7 and GPA 3.78
Bio sciences-- sGPA 3.65 and GPA 3.71
Humanities --sGPA 3.61 and GPA 3.70
Specialized health sciences-- sGPA 3.61 and GPA 3.70
Social sciences – sGPA 3.58 and GPA 3.66
Other** – sGPA 3.65 and GPA 3.71
**includes pubic health, business, engineering and any major that doesn’t fall into one of the other categories plus all double majors