am I doing some thing wrong?

Megan 💕
So me and my fiancé have been trying for more that 3 years now to conceive our first baby, we had sex every other day to start of with the first year, then we started to doubt ourselves that this wasn't working...
Since beginning of last year until around November we stated to take things properly again, I started taking seven seas, then pregnacare and even vitamins, and then still nothing. So gave up!
Now we want to start trying properly again this year, I've been trying to take all the recommended vitamin, folic acid, changing my diet... but nothing still 😔
Thinking we should just stop and see if it happens on its own without expecting it 😔
I kind of think this is al my fault as I only had one shot of depo injection until we wanted to start for a family...