(NewsNation) —An American teacher behind bars in Russia has broken her silence.

In a letter from a Russian prison, 46-year-old Sarah Krivanek says “the road has been very hard” since she landed in legal trouble nearly a year ago.

She says her health has gotten worse and she has no medical care.

“I want to come home to you all. And when I get home, I will tell you everything. I can’t do that in a letter,” the letter reads.

She’s currently serving a year and three-month sentence in connection to assault charges from a domestic dispute. Krivanek was arrested last fall after she reportedly scratched her Russian partner’s nose with a knife.

However, her friends believe she is the one who was abused and was defending herself. According to relatives, Krivvanek suffers from a kidney disease that can be deadly if not treated.

“I’m just so worried about her because she’s not able to tell us exactly how severe her health is,” Krivanek’s close friend Anita Martinez said Tuesday night on NewsNation’s “Banfield.” “I was happy that she’s alive because I didn’t even know that. I didn’t know what was happening with her.”

According to Martinez, the prisoners rely heavily on outside sources to provide basic supplies.

“It’s my understanding that they give them a uniform and basic food. That’s it. Everything else they depend on family and friends. But the problem is that with the sanctions that are in place in Russia right now, we’re not able to send anything because they can’t have any currency or anything from outside countries,” Martinez said.

Martinez believes that a human rights organization will visit Krivvanek soon, but she’s worried that if they don’t, her situation could be dire as winter conditions worsen.

“I’m just hoping they (the U.S. embassy) do something to help get her home before it’s too late. I know she just has a few months left on her sentence, but depending on the severity of what she’s dealing with right now, I don’t know if she has a few months left, period,” Martinez said.