Low mood after diagnosis

I received my diagnosis in February. At the first I felt positive and relieved. But the more I learnt and the more I thought about I started to feel down. I'm finding it hard to shake this feeling and it seems to be getting worse. Pre diagnosis I had no idea or awareness of autism. I'm 25 now. I can't help but think how different things could have been. I'm finding it hard to focus on the present or future. I just kind of feel sad all the time. Is there a way to make this go away? In a way I'd rather not know because there doesn't seem to be any support or help. Not sure where to go from here.