My (24M) girlfriend (23F) is staying at her sister’s (27F) until I “admit I have a problem and get psychiatric help”

This all started earlier last year. My parents were going through a rough divorce, and my dad attempted suicide which left him not all there mentally even though he survived. I basically have had to take care of him, and it brought me a lot of stress as I am a fulltime PhD student living off a stipend and nothing more. Between that and my girlfriend's income, we live! decently in the city we're in, but there's not much room for this kind of responsibility financially. It definitely took a toll on me, and I got really depressed after a while and started struggling with severe insomnia.

I guess that is where this all took the biggest turn. My girlfriend was very supportive at first, and even when I was dealing with that she understood. I've done my best to keep her out of it, which is why I initially started sleeping on the couch to not disturb her with my tossing and turning. Eventually I just gave up on sleep all together and started going on night drives. She was aware of this and didn't have any issues with it, but eventually I started to be gone for hours and she was getting worried. Understandably I guess. We had a talk about it last month, and I explained what I usually do to her in hopes of clearing her mind. This is the part of the situation that I admit is difficult to explain.

Basically, after I'd been going on these night drives for a while, there was one night where I came across a young woman crying outside a gas station. I felt bad for her and had nowhere to be, so I stopped to see if she was okay. Turns out she was a minor (16) and had a bad home situation. I offered to give her a ride somewhere because that part of town (or really any at 3 am) isn't particularly safe for an underage girl to be walking around, and she hesitantly accepted. I drove her to some house on the other side of town and that was all there was to that specific interaction. The girl was obviously nervous the whole time as I guess any teenage girl would be in a strange man's car, but I really just wanted to help. And it felt good seeing her relief when I actually took her where she wanted to go. SO basically after that, I started driving around at night and looking for other girls/women that were by themself and might need a ride. It took a while to actually find someone (which I guess is good?) but eventually I did, and it just kind of became a night hobby where I would drive around and give these girls rides whenever I could find them. Especially on the poorer side of town, I started to do this regularly. I can admit it's a weird thing, and a lot of people may wonder why I didn't just uber or something, but that isn't the same. I specifically enjoyed helping people I felt actually needed it, and I got this unexplainable enjoyment out of seeing them go from anxious to relieved every time they got out of my car.

I explained that to my girlfriend, and she said it sounded extremely predatory. Which I was confused by because I never even touched any of the girls. Especially since several of them were underage and I'm not like that. She said it didn't matter if I did or not though, and it was just inherently predatory/weird. We had a big argument, but eventually we made up and I agreed to just stop going on night drives all together. That was about a month ago, and things were awkward the entire time, but we lived together fairly peacefully until earlier this week.

I ran into some unexpected financial trouble last week when I suddenly needed new tires, and it put me in a bit of a bind with taking care of my dad and all. I ended up having to take on more credit card debt to get everything done, and basically after that, I was just extremely stressed and ended up doing another night drive. I didn't even pick up any girls, but my girlfriend was waiting for me when I got home (around 5 am) and we got into a big fight. She thinks I've been doing all that again (I haven't, this was my first drive in general in all that time) and she ended up just leaving to go stay with her sister. Basically, she said she is willing to work things out, but I need to get psychiatric help and "stop preying on vulnerable women even if I think it's harmless as a means of coping." I am already seeing a therapist, so I don't really know what else to do. I don't see that earlier behavior as predatory at all, and I haven't even done that in like a month anyway. She just doesn't believe me. What more can I do besides continuing therapy?

TLDR – My girlfriend has temporarily moved in with her sister because she thinks I am coping with stress/depression in unhealthy and occasionally "predatory" ways. She is willing to work things out if I get help, but I am already in therapy and don't know what more I can even do.