Not Sleeping

I know each baby is different..But my son, who will be 8 months old tomorrow is still only sleeping about 4hrs in a row at night...and some nights he is up every 20-40 minutes. I am exhausted. My daughter didn't STTN (8+hrs) until she was 33mos, but at 8 months, she was at least doing 4/5hrs regularly. I'm at my wits end. I've tried everything. Does anyone else have this issue? I'm so tired, I'm always angry, and I know my anxiety and up. It's not just me right?!