Welcome LPoppy! And thanks so much for sharing your experience.
First of all, congrats on graduating your dilation program! Secondly, congrats on knowing your body, and being thoughtful as to how to move forward with penetrative sex. In fact, you are so knowledgable that you answered your own questions! At Maze, we always recommended dilating up to one size larger than whatever you chose to insert (ie your partner’s penis, a vibrator, etc). You should dilate with that just before penetration. In your case, you can do it by yourself privately, next to your partner, or with him (this is entirely up to you).
Additionally, we strongly suggest the use of lube (and you can’t use too much!) during penetration of any kind.
Another possible factor: you say you’ve only been with your partner for less than a month. It’s not about quantity but quality here – you want to ensure that the person you’re having sex with is supportive and someone you trust. If all of that is in check, that’s great! If not, remember that this is your body and always your choice how, when, where, why and with whom you engage sexually.
Also take note – it’s not unusual at all for the first couple of times out of the gate to seem awkward and mechanical. Be patient, take things slowly at your own pace.
If we can be of further help, reach out to us for a free 10-min consult. Take care and keep on keeping on!