How do I have a gspot orgasm?

Me and my boyfriend have literally tried everything! everything from relaxing and him penetrating me all the way to me rubbing my clit while he penetrate me. but I just don't know! and when he goes down on me it takes me so long to orgasm. he told me the other day that sometimes his jaw locks because of how long it takes but he keeps going because he loves me and he wants to satisfy me. someone help I feel bad because when I give him a blowjob my jaw locks and he says I can stop and I do because the pain is unbearable. I could only imagine what he goes through when his jaw locks but I never know when it does and if I did I would tell him to stop immediately. help answering all these questions could help both of us!