I have this problem with my girlfriend, During she always needs me to lick her and she comes rarely

My girl friend always makes me lick her before , but it okay with me . But she ask me to do it for about 15-20 min whereby sometimes makes me feel down. Another thing she rarely comes and blame me for comming too fast . but i guess its okay for me. As my lasts about 15-20 min when pumming her.Another thing that we are staying together and she ask for 3 times a day. can some one advice me how to makes a girl comes or is my girlsfriend is a hyper persan?