Not super helpful, but I thought you might feel better to hear I am in the same boat! I've applied to all the studios I can find and have heard nothing but silence or rejection. :/ It's disheartening, for sure. I'm replying to bump the thread and to follow so I can keep up with any other advice that comes through. Best of luck to you!!
Find a "local" studio - bring your portfolio - ask for a tour and maybe some guidance. Most animators and set builders are really open and nice people, who will be happy to spill knowledge. But you have to show up, at least that's my experience. Make them talk, and then if convenient show some stuff you made. Loose fotos in paper are great, rather than a portfolio, where you have to bend over and turn pages, they can be spread out on a table, and shown around!! If they show interest and ask, show them some animations. The entryway would normally be in the set building, as an apprentice. With little or no pay. Most studios are small and even so overwhelmed with applications. So be brave and show up without appointment. Tuesdays between 10-12 are good from a working time perspective. Monday's goes with the weekly planning and job assignment, Tuesday people are on their own workplace, checking inbox and preparing the work, Wednesday and Thursday they are concentrated on working, and Friday they are on them way home.
If your going to send a application, deliver it by hand yourself, preferably on Tuesday's and get a tour or an appointment.
Best of luck :)