Suggest Cure For A Small Bulge On My Vagina

I noticed 3 days ago a small bulge on my vagina lip. 2days ago it opend by it self and is beginning to leak a little. I have a long history with abssess and thought it might be a bartholin cyst. it looks as if a layer of skin is missing. I would like to know if it is that or maybe even an std. could you please lead me into the right direction for this.