Get yourself worked up using fingers or a vibrator, as you're nearing climaxing start rubbing the well lubed dildo again your pussy. As you experience the climax exert pressure on the dildo enjoying the sensations of it starting to penetrate your pussy. Keep steady pressure until it becomes uncomfortable then let up but keep rubbing and start attempting to insert it again, going slow, don't ever force it, just let your pussy slowly adjust to it until you secede, it may take several sessions but in time you'll accomplish your goal.Note: use plenty of lub, warm up the lub and dildo first before using as it'll feel much better and facilitate entry. Have fun and keep us updated.
Oh, the journey has just begun! Many of us who've gone down that road can tell you, limits are not permanent. Every time I've thought I hit my limit, I eventually/or soon realized that I wanted or could take more. Your frequency of play/practice is important. The more often you do it, the easier it becomes. Just take a day or few days break when you become sore. Then get right back at it. Your limits will slowly extend & always be just out of reach. I've been playing for years & got to where a 2¾" diameter Ace of Spades plug was do-able, with work. Getting to a point in life where I could have more play time allowed me to progress beyond that. In July I advanced beyond my 2¾" limit, to a 3.21" diameter dildo that's almost 7" long. I can now take that entire length all the way in & I'm already looking at larger ones. I do try to make a point of playing at least 2-3 times a week, if not every day.
Don't rush it. If you really want it, you will get it in. After several min. of fucking my asshole I was able to accomodate our biggest dildo , then my wifes gloved and lubed hand. When she saw that I could take our large dildo to the balls, but her bracelet didn't reach the bottom of the shaft, the fisting lightbulb went off in her head and her fist up my ass.