What Causes Lump At The Vaginal Opening After Having Sexual Intercourse?

I recently had sexual intercourse for the first time.The day after, i experienced really light bleeding and found it painful to walk (there may have been a vaginal rip ? ). 2 days later, i had a yellow/white discharge which was more than my usual amount. When i woke up this morning i had a discomforting pain from my vagina, when i attempted to wipe myself after urinating the pain increased and its uncomfortable to sit down, i realised that there is a lump at the entrance of my vagina almost completely blocking the opening and it is painful to touch. I dont know what has caused these things ?