Bad GPA and 6 years of undergrad

Hi all, long time user but posting on an anonymous account for privacy reasons.

Long story short, I have never been a great student. I have worked hard to get some solid work experience as an intern, and have worked at two different investment banks for 5 months each, a LMM private equity fund for 6, and they all offered me the opportunity to stay on as an intern beyond that (small shops, no FT analyst positions available - for whatever it's worth, they did say if a spot opened up they would reach out down the line). I have great letters of recommendation and references. However, I am facing a bit of a hurdle and I don't know how to explain it.

In short, I went to three different universities and it has taken me 6 years to graduate. I have been diagnosed with depression and anxiety 8 months ago, but have never mentioned it to any prior employee. It is never noticeable at work, as I keep my personal issues to myself, and no one has ever expected it. In fact, I've gotten great reviews everywhere I worked, not because I am the smartest (I am far from it), but because I am a decent grinder. I never had problems getting internships because I was never asked for my transcripts (I never worked at an EB/BB, and even the MM IB I worked at didn't request it). On average, I have a 3.2 from each school. My question to you, is how do I explain my lengthy undergrad experience? I have a good resume from an experience standpoint, a 3.4 GPA at my current university, but I don't know how to proceed. Do I bring up my entire past in interviews, or wait for it to come out when companies request transcripts? I have been dinged before automatically when I mentioned that I transferred twice, and it pretty much ended the interview on the spot (the only time out of 10 IB interviews I didn't make it past the first round).

The reasons I transferred are as follows, I started at a great STEM school, but STEM wasn't for me, and I transferred to a semi target and took the prerequisite finance courses. I did well (had a 3.75) but botched one class and failed to gain entry into the B school. Now, I realize how absurd that sounds, but at this particular university it is how they weed out a lot of students, and I know countless others this has happened to. I tried everything I could think of to gain entry, but nothing worked. Devastated, I transferred again to pursue a finance degree from a non-target and have been doing fine, I have one quarter left. Everyone told me when I went from a semi to a non target I had no chance of getting into IB, but oddly enough all of my experience has been gained without a single connection in the industry (just hustling and cold calling 100s of different firms) and doing whatever it takes to get the position.