I couldn't bring myself to do so either for the same reasons. And I didn't want to be told that I was asking for too much/something I'm not "allowed" to have.

I ended up going in to the counseling service's walk in "urgent care" that my university has for students because it was looking like my insurance wasn't going to pay for any more IOP and I was feeling like I was going to be all alone again like when I originally got terminated and didn't have any support system. The therapist there was really really good and understanding and had a background in like attachment stuff and he spent a really long time talking to me. One of the things he brought up was whether seeing my therapist twice a week instead of once a week would help. I said yes, but that I couldn't bring myself to ask because I was scared of being told no.
He offered to tell my therapist that he'd asked me whether I thought it would be helpful and I'd said yes. It's not uncommon to sign a release so they can let your therapist know that you went in and stuff. I agreed to it because then it wouldn't be me asking for it.

My therapist brought it up the next session and asked if that was something I'd want to do. I said yes, and so that's how I moved up to twice a week. It originally seemed like it was going to be a short term/crisis period thing.
But he's been continued to offer twice a week when we schedule.
Yesterday we scheduled for the first few weeks of October and he asked about when would work for me and he didn't say anything about once a week vs twice a week and I've always kind of waited for him to offer. I eventually worked up the courage to ask if I could still do twice a week and he said yes and he didn't sound annoyed by it/begrudging.

tl;dr: it's complicated and I kind of asked but kind of didn't

I've found it really helpful. It's kind of like a sanity check that keeps me from catastrophizing/working myself up too much between sessions. If I have an entire week I'll have convinced myself of a lot more awful things and talked myself into some stupid stuff. This way I can get things out there with him before I manage to convince myself to act on it.