If you do not have access to attending an actual school for design, online courses will help you scale up. Some are comprehensive while others are tailored for a particular skill. The advantages paid courses have over the free ones include personal teachers, reviews, more materials and certificate which you can add to your resume.
Because most of the courses are online, it might not be easy to finish up in time. It'll do a lot of good for you to set reminders for doing these courses or have an accountability partner checking in on you.