How do I stay in my lane and know where I'm going?

So I've been driving at least 3 times a week since late May and need to get my license within the next 2 weeks. Somehow, it feels like the more I drive, the worse I get. I've been finding it hard to stay in my lane and knowing when to turn.

It's really hard to see things in my mom's truck since it's so massive. I'm entering my senior year of college, and I want to be able to drive places my last year there. In my mind, the quicker I get my license, the quicker I can get a small car that I feel comfortable driving. My family has bad credit, so it needs to be in my name, and I also don't want to rely on my mom for my car payments. I've been aiming to take my exam every Monday/Friday, but my mom tells me I'm not ready and need to stop rushing.

I have no social life. The whole summer has been work, working on personal projects, a poor diet, and lack of sleep (definitely not helping my driving).

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I really just want some advice and words of comfort.

Thanks all