Any mental health professional who has been working for a while has probably heard it all. Some younger people think that by admitting sui or SI thoughts will get them thrown in a locked rubber room and pumped full of drugs. This is not true.
Your MH worker will understand and try to help you figure out how to cope with life and develop alternatives to harmful thoughts or activities. Don't be afraid to reveal what is really going on inside you. Typically they won't even advise inpatient unless hurting yourself or someone else is imminent without intervention.
Good luck to you and remember to be kind to yourself.
Oh, and a lot of people find it easier to write their thoughts out and let their T read it.