ok it goes a little something like this...

meet girl a couple of months ago, girl is very nice, girl gives me her number, girl texts me, i text back, this goes on for a while. All is good. i then stop texting back because basically im an idiot, but thats not the point. My question is how do i make it seem not weird txting her after all this time to ask her out, what would be a good excuse? would it be a bad idea to say i stopped txting her because i had a girlfriend at the time, would that be a valid reason? or would she just think i was just a bellend for ignoring her for someone else?

is this a lost cause, have i missed my chance?