A lot of people think they know everything about medical stuff and offer "advice" that really is of no merit because they really don't know what they're talking about. The diabetes really doesn't have anything to do with the ability to get pregnant.
It can be a long tortuous process, there are trying to concieve forums out there where you will find people that are going through it too, and they can offer ideas on things to try.
If you've been at it for a year or more, see your doc. They can investigate the cause of the trouble.