TTC for 10 months

My boyfriend and I have been TTC for 10 months. We have sex almost everyday but still nothing. I have 1 child who will be 3 soon so I know I was able to get pregnant before. Is it possible that I no longer am able to conceive? How do we know if it’s me or him who is having a fertility problem and why is it taking so long to conceive? Does anyone have any suggestions to help me conceive ASAP