Hi kim,
what you're going through is perfectly normal and healthy. It's understandable especially without much previous sexual experience for your body to act and react this way. I also suspect you have a lower sex drive, which is nothing to be alarmed about.
Not all women can experience orgasms from vaginal intercourse, actually most can't and have to resort to clitoral stimualtion. This is perfectly normal. Likewise, some women can not achieve g-spot orgasms, or find it too sensitive and possibly painful.
It is safe for him to use his saliva as lubriant, however keep in mind that the bacteria in his mouth, espeically if there are sugars there can multiply into a bacterial (yeast) infection. So be sure to keep your hygiene up. I advise using a proper water based lubricant such as astroglide. Vaginal dryness is a common problem, but difficult to diagnose over the internet. It can be psychological, or physiological, or a combination of the two. Without proper lubriant, penetration can become painful and irritable. So be sure to keep proper lubricant nearby. Vaginal dryness is said to affect 48 million women across america. It is also a common condition as women approach menopause.
I do advise you to be honest and up front with your boyfriend letting him know that you're unable to reach climax through vaginal intercourse, that it's not his fault.. It's just the way you are, however.. You do enjoy it and that doesn't mean you don't want to share this with him.
Breast sensitivity is linked to many things, for the most part women with smaller breasts and aerolas are more senitive, and react more to touch. Larger breasts and aerolas results in stretched mechanoreceptors (touch receptors), and often little to no feeling or stimulation. Also note there is a certain degree or erotic stimulation that is mentally triggered knowing that he is caressing your breast, if you mentally are not stimulated by this, then physically, you will also not be stimulated.
Hope this helps.
Be safe,
justin