please? advice on relationship/mental health

I started to have feelings for my best friend roughly a year ago, they are currently and will be at another country for the next 5 months. It was torturous living via internet with them for the past half a year. I told them about my feelings 3 weeks ago. They were shocked and confused but generally accepting. We discussed a lot where our relationship should head. Since it continued to be emotionally draining for me, we decided its better to stop talking for a while.

My mind felt genuinely more free last week, tho of course I was nervous about their life. The thing is they werent particularly happy with the new place, experienced troubles adapting to the new society. They always told me they cannot find anyone to talk to which is vital for them to let thoughts and feelings out. This morning something clicked and I wrote to ask how they are doing. Now I found out that they had several panic attacks and wanted to overdose themselves with pills. They had problems throughout their stay, but this was worse than ever. I am very scared, I know I cant help them other than being there on the phone. Another problem is all the stressful thoughts and heaviness that I was trying to escape are back, so my mental state suffers from our contact. But Im deathly fearing to stop talking again since their abandonment and mental state are even worse.