Pablo needs medicine

Hello, I'm Pablo and I'm a rescue dog that was saved from the humane society not but a couple months ago. Right when I got to my new home I started having worms (ew!) but luckily my new parents got me taken care of! Now not long after that went away I started losing hair so I went back to my doctor and they had to scrape some of my skin to test it (ouch!)  The doctor said it's mange, which they can treat but it takes medicine and monthly testings (expensive!) to get rid of it and my parents are getting low on funds. Would you please help? Much thanks if you can! - Pablo the dog