Ever feel demotivated to work in your company but you cannot quit ur job?

I started working almost 5 months ago. Things seem to go downhill ever since then. I have no solid job responsibility and often i am just doing administrative work like compilling stuffs, and laminating items. Although occasionally i get something that is related to my job scope, it only occupies like 30% of my time. I cannot seem to do much. Ive talked to my boss but my situation remains the same. On my part, i realise i am incapable of discussing in depth technical stuffs due to my lack of knowledge because i am new to all these. I am very demotivated and made quite a few silly mistakes here and there but nothing serious. I cannot quit this job yet as i am still searching for one. Worse still, people often pass by my desk looking at what i am doing and start saying bad things behind my back. I feel like resigning soon. What will you do to change this situation?