Meditation and body scan

I have been practicing what I believe is insight meditation for over 5 or 6 years now in the Mahasi tradition but still very frequently I feel like I'm not doing it right or something. I suppose I thought that I would see some kind of change or have some insights but nothing much has changed and I can't say I've had any insights into the true nature of reality which is so often emphasised and mentioned. I've started to do body scans but I'm unsure if I'm doing it right. I sit for a while and notice the breath then I start at the top of my head and go down the body part by part ie crown of head, back of head, forehead, eyes, nose, lips, chin, neck etc. But I have difficulty with this. I'm unsure how to focus on a body part apart from trying to see it in my mind. I don't feel anything anywhere except for the air going through the nasal passages, sometimes the eyes flutter a bit, the abdomen rises and falls and the hands sometimes tingle or pulse. Everywhere else feels completely dead. Maybe I'm completely out of touch with my body and its sensations. I know they must be there but why can I not focus on them? Also sometimes I'll start at the head and then I realise I have wandered off for so long that the mediation is nearly over so I cannot even manage to scan the body at all! Please don't tell me to read the scriptures or find a teacher. The scriptures bore me. I'm not a religious person. They are just so repetitive and convoluted that I don't find them helpful. They send me to sleep, and trying to find a teacher is impossible. I have attended Sanghas regularly on occasions and nothing ever comes out of it. I don't know how to approach people and say can you please be my teacher. The people at the Sanghas didn't seem to be open to having students.