Yikes.
OK, cracks have two likely causes. One is latch problem, the other is infection. Do you have a handy LC you could talk to? Or knowledgeable nurse/GP?
Sometimes ties can grow back, might be worth having a look just in case. Doctor can swab for infection and there are creams you can try. Pharmacist might even be able to advise you on broad spectrum cream that will knock out likely culprits.
Shields might help in the interim, but won't address the actual problem, unfortunately. Pain relief and discs and so on might also help you get through till you can get them properly healed, so probably worth trying all the ideas You will need to fix the problem, however, or it won't get better.