Dating

I recently ran into an ex-boyfriend online and he keeps pressuring me to reunite. We split on somewhat good terms. Although I was a large person when we dated, I'm about 30lbs larger now. I am so ashamed for him to see me like this. I keep putting him off by telling him that my work schedule simply won't allow it. I keep telling myself that if I can get him to wait one more month (having surgery on the 12th) that he'll be seeing me at or near the same weight we split. I know that he's a great guy and I am more than willing to give it another go, but how can I get past this shame?