Development

So my son will be 8 months in a couple of days. He was born at 35 w 6d. He’s come a very far way, but I still feel like I’m not doing enough to help him along. It took him until he was 7 months to fully lift his head. He doesn’t reach for things. He holds onto toys for a moment but then drops them. But everything else he’s excelled in. I just kinda feel like I could and should be doing more but being a first time mom I don’t know what else I can do. The pediatrician wants him to see a physical therapist but we’ve been to so many different specialists that it just makes me feel like I’m doing a crappy job at being a mom. Any advice??