afraid he's TOO big :-(

So i've never had this problem before. i love rough sex and being throat-fucked and all that jazz and i'm usually able to handle it really well. But with my new boyfriend (i wouldn't call him my Dom yet, but he's catching on quickly) none of this is even remotely possible. He's insanely umm...well-endowed, and i don't just mean above average, i mean freaking porn star huge. In theory i thought that would be awesome, but in practice it just makes things really difficult. i'm pretty petite to begin with so it makes him seem even bigger. We're limited on which positions we can use, he can't fuck me very hard because the whole thing doesn't fit without some discomfort, i can only take about half of him in my mouth before i start gagging (and my gag reflex has rarely been a problem before), and basically it's something of a buzzkill. i hate it because i want to continue on this journey to being his submissive- he's fun and sweet and considerate and gorgeous with a lot of natural Dom instinct that i imagine is just going to get better with time- but it's hard to feel like i can adequately please him when i can barely handle the sex. Does anyone have any advice on how to deal with this? Are there toys or exercises or something i can do to train my body to accommodate his size? Thanks in advance for your help.

Have you talked about this with him? If he is that well endowed, you're not the only woman who's had trouble with him. Men who are large get frustrated because of themselves, not because of the woman they are with...so the best thing to do is to talk it out and find out what will please both of you. :)

you can often get some large dildos to practice with. I've had a similar issue in the past when a well endowed dom wanted anal and I daren't try it despite having anal with others in the past due to his size

I think John Holmes was 14 inches.

You have a boyfriend who is so "porn star huge" that you, a petite submissive woman, cannot begin to satisfy him. The problem appears intractable given the experiences you describe. But here are two approaches you may try:

Fellatio: You cannot take more than half of his member without gagging. You ask about measures to expand your oral capacity. That is impossible. Instead, take him in his flaccid state. Take all of him orally just after he has come vaginally (see below). He will be especially pleased at how quickly he resumes. Many other women find this the only way to take an entire member.

Vaginal Sex: Here you will succeed. Persist in your search for larger dildos to gradually enlarge yourself. Keep in mind that your vagina is fully capable of expanding to a sufficient diameter to accommodate the head of a newborn baby! Look at some of the literature published on the subject of preparation for natural childbirth. You are on the right track.

Hopefully this advice will also be useful for other women facing similar difficulty.