Feeling Worthless and Alone: My Family's Disregard for Me

hi guys, first post here, and it’s a lot. VENTING WARNING!!! — i’ve been uncontrollably crying for the past hour or so, and i just don’t know what to do. the thing that finally pushed me over my limit this week was my mom telling me that she smoked while she was pregnant with me. i was angry and hurt, and she told me to "stop lecturing her" and that she "didn’t do anything wrong." her and my sister agreed that i had ruined their conversation and went upstairs to talk without me. i was so angry, but i just burst into tears after they left. i knew they never cared for me, but it hurts when they leave me alone like this. i just feel worthless. i’ve been struggling with suicidal thoughts all week, and i don’t have any friends that i can talk to reliably. i don’t have a therapist. i don’t know where to go or what to do.