You say that you practiced all the techniques at least once. You should know that you need to be consistent with techniques. If you want to test one, you should do them at least a few weeks. Also, overthinking can in fact make it harder. Work hard, be confident, and don't worry about it. LDing is easy, you just need to get the hang of it. Don't ever get stressed over it, that will only prolong the time until the next results. As for your DJ: it can make the results less, but not necessarily. There are a lot of LDers (including myself) who have succes without keeping a DJ. Some people however really need it. So it can be a cause, but not necessarily. But it is not impossible to LD without a DJ or something