Oh LysnDan . Please never ever feel ashamed. Tell people whatever you have to, but never feel ashamed. My twins have just turned one and have just reached the 7kg mark. People are forever commenting they are tiny. On the weekend, we took them for their 12 month needles and the nurse walked in and said "Oh no! I was told it was 12 month, not 6 month! I'll have to get new needles out'. We said "No, no it is 12 months' and she said "Are you sure?'. She apologised straight away for being insensitive but people really do say the stupidest things. For a while I got the shopping home delivered so I didn't have to put up with people. Now, I just smile and either nod, or say "I know! It's lovely they are so little. They are like my babies for much longer'.
As for the reflux, my DS had very bad reflux and he was born almost at full term. My DH developed a hernia soon after birth. None of it is your fault.
Please don't let the comments of stupid people that you will probably never see again hurt you. You have your lovely little girl and that is all that matters xx