With history and English together you'd need two different approaches, and that's the real problem nobody's mentioned so far. English is a subject where timing is everything - if the teacher corrects you on the spot while you're speaking, like you said, you fix the mistake right away and don't carry it with you. History instead is more about understanding and analysis, where you often need to sit with it and think things through afterward, maybe read the sources together. Online works better for history (you can open documents, maps, historical videos directly, share your screen and work through it together), whereas for English in-person is definitely superior if the goal is to speak and not embarrass yourself at the exam.
In Milan you're lucky to find teachers in the flesh, but the logistical problem is real - commuting eats up time, especially if you don't have much margin before September. Online like Superprof frees you from that, you can do a 45-minute lesson without losing an hour to travel. The real disadvantage (and here I'm going by what I've seen with people around me) is that in person it's harder to "slip away" - you're sitting at the table, the teacher is looking at you, you feel the weight of the lesson. Online it's easy to get distracted by your phone or lose focus because maybe the video is small.
One practical thing: if you go online, make sure the platform allows decent video calls and that you have a solid connection. If you pick someone in person in Milan, check that they're not too far from where you normally study, otherwise it becomes a hassle to get there twice a week. For history you might even be fine with someone online who knows the Italian curriculum well, for English really better with someone who can hear your accent and your speech flow.