generally speaking, you paid for a nice computer guidance and assistance system, with a small telescope attached to it. however, your problem relates directly to the focal length of the optical system of your scope - you have a short focal length whose strengths would be for wide field observing. this is why you are having to use a very short FL eyepiece to acheive enough magnification to see any detail on objects such as jupiter. 4mm eyepieces are notoriously difficult to use due to very limited eye relief.
for planetary observations, you typically would want a long focal length scope where you can utilize longer FL eyepieces with greater eye relief. also, a scope with a larger diameter objective will, by gathering considerably more light, greatly enhance your observing enjoyment.
however, there are many wonderful and interesting things to be learned and seen with the scope you have, and i encourage you to use it's abilities to the fullest. brighter/larger objects such as the moon can be a lifetime of study and visual enjoyment all by themselves. likewise, observations of the sun can be totally fascinating (there are very inexpensive ways to construct a solar filter which allow for safe direct viewing of the sun).