Lump near vagina

Someone please help me I’m so worried. I’m 17 and recently lost my virginity, most time I’ve had sex since then it’s been uncomfortable and I’ve often bled after it. Today after I had sex I noticed that there was a very big squishy lump just above the opening of my vagina and I don’t know what it is. Can someone please tell me what this could be as it’s appeared before after sex and only ever appears when I’ve had sex. Please help I’m really worried as I’m new to this and don’t know what it is