Well, I have never been heartbroken, cause I never truly experienced a true legit love which I hear in stories... what I encountered are few breakups, but you can say I had admiration and took a big liking to them... but not necessarily a fantasy love I would say that leaves my heart aching so much...
Anyway, here are my few simple advices for you:
1- IF you are new to the dating world, YOU HAVE TO go out and date other people just for a period of time, DO NOT aim for a new relationship very fast, but at least try to mingle with others for some time...even if it was just casual company and fun with someone without anything too serious... The reason I say that is, when you are NEW to the dating world, you can fall EASY to the illusion that you are in love, but what you're experiencing is something else... which is VERY TRICKY...and dating diffrent people for some period without the intention of being in a relationship can clear things up for you...
2- However, if you have been in the dating world for a good while, and you dated many others before... but this person, feels so special to you... I'm sorry man, I cannot really help you with good advice regarding true love cause I never was in that position myself... BUT, I must say that if she LOVES you too, but the only obstacle is big dick... I must say that she doesn't love you, not one bit.... and you have to ask yourself... would you be okay to actually be in a relationship where love is ONESIDED???? cause let me tell you one thing that NOT MANY PEOPLE SAY..... people who only care about size in bed, are the WORST in bed... because to tell you frankly, they think that sex is JUST LIKE in porn movies... which is 180 degrees opposite... There are PLENTY of ways to pleasure a woman or man (if you're gay) without needing that 8-10 inches dick.... and by Plenty and I mean it... PLENTY.... you can be very resourceful in bed (hands, tongue, even freakin' dildos if needed...etc)... it's fucking 2020
Point is... if she truly values you for who you are.... you both would find ways to pleasure each others WITHOUT splitting up...
That's like being in love with a petite woman, but saying "well, I cannot handle your small boobs, I only want big boobs" so we're splitting up LMAO... that's how the dynamic is going right now my friend... So, ask yourself, would you be ready to try be in a relationship with someone who will not have a shred of feelings for you? and it's onesided? or would you rather to move on... try finding different match and build that spark/connection with a genuine person?