Put away the keyboard. Think about what you're going to do, chart it out, work through the logic and then, when the entire construct is before you, you start typing.

Yes it will take longer, you're a junior, enjoy that nobody expects you to do miracles (yet) and take the time, you'll get it back when you're so used to working through logical problems that it happens on its own as soon as you hear about the problem.

Cutting corners and "hacking a quick solution" without fucking over the entire system is an art form. Before you do art learn your damn craft.