I will add make sure you squeeze out the excess air first. It will help a lot with the cramping and urgency feel. Squeeze slowly from the tip over the sink until the medicine comes to the top, then hold it there until you insert.
Once you get use to the feeling of having them in you, it will be easier. Just keep squeezing your butt as tight at possible ( good work out!) to make sure it stays in until you get use to them. They do work! Give them time!