I'm doing christian fasting for spiritual purpose to reduce my severe anxiety and suicidal thoughts. However fasting is stresfull so i'm afraid that it can make my anxiety and suicidal thoughts worse. Maybe i should do a semi-fast? (idk if that's correct name for it)
The Eastern Orthodox are arguably the most ardent fasters of any group of Christians. But one thing every Eastern Orthodox Christian I've spoken to on the subject has said when talking about fasting, is that if one isn't in good health they shouldn't fast. The very young, the very old, the sick, etc are exempt from the expectation of regular fasting (and there's a
lot of regular fasting in Eastern Orthodoxy). That's because fasting shouldn't be harmful to yourself. If fasting is causing you harm, then you shouldn't be fasting.
And given your anxiety and depression, and that the fasting is making things worse for you, sounds like a good reason not to fast right now. Don't fast unless you
can fast.
If you want lighter fasting, instead remove one or two kinds of food. For example, during the Lenten Season many give up meat and dairy. It's why Friday, a regular fast day, in the West has been described as "Fish Friday" because meat is given up, but fish isn't considered meat for traditional fasting purposes.
If you want to fast, try a lighter fast; but hurting yourself isn't good. Not only is it not good for you mentally and physically, it's not good spiritually either. Perhaps instead of fasting right now, you could try a prayer discipline without the fasting. A simple prayer discipline of praying the morning and evening prayers can do wonderful things. It can be as simple as you want, you could follow something like the Daily Office if you want, or you could simply take a moment to read a portion of Scripture and a few moments to pray and reflect on the Scripture reading.
-CryptoLutheran