Where are you geographically? In Silicon Valley only a few players (and they are generally notorious for it) would require you to come in at 8:45. You're also

Where are you geographically? In Silicon Valley only a few players (and they are generally notorious for it) would require you to come in at 8:45. You're also internalizing things that may have nothing to do with you: between the ages of 18-25 jobs and relationship will often not work out for you - and even if you are at fault, this is the best time to make mistakes. (Your ex-gf is a human being just like you, with her own flaws and interests - and different employers have their own HR policies, some of them bad some of them good; and the "obligated to come back" is completely false.)