Are textbooks and books enough to get to business level Japanese?

I’m beginning my shukatsu soon as class of 2027. I’ve been in Japan since I was a kikoku teenager starting with 0 Japanese. I’ve gotten through middle school to college in Japan so I can get around fine and do basic jobs with not much problem, but I’m pretty anxious about doing hard interviews in Japanese and working in an office. I’ve signed up for shukatsu websites and have already gotten invitations for 説明会 and 早期選考 interviews but I just don’t have confidence in my Japanese skills. It’s really my fault because I never actually sat down to seriously study and brush up on my Japanese skills the whole time I was here. I did study a lot of subject in Japanese but it’s not the same as purely studying Japanese. I’m starting now, do you think it’s enough to study N1 and business Japanese textbooks on my own to get to a reasonable level where other Japanese people wont look at me weird for not knowing the language as well as they do? Im planning on applying for IT jobs as an SE or programmer. Please give me some recommendations on books if you have any.