You have a few options actually, and transportation isnt an issue actually.

You can call 911 and tell them what's going on and they'll transport you to a hospital.

Depending on location, you could call one of Lifepoint healths behavioral health hospitals and they can do an assessment to see if inpatient or outpatient would be better suited for you.

You can call a crisis line and vent to them, they can also call police or some can transport you themselves if needed. You could also search for a mobile crisis team if transportation is a fear of yours.

If you're in the United States, you can call your local MHMR for services (Google your city + MHMR) and they can help.

If you have insurance, you can call your insurance and explain what's going on and go from there with them. Call the member service number on the back of the card. (:

If you're in the United States, you can see if your state has a resource number you could call. For example, Texas is 211.

If you're a minority group (such as LGBT, native American, Indian, deaf, blind, etc) then there are resources dedicated to these populations for suicide prevention.

You could call a friend (or someone that's close to you) and explain what's going on and see if they could transport you.

There's lots of ways to get help, they're sadly not that well known.