Difficulty with menstrual cup

I just got a Lady Cup (greencup) off ebay and am using one for the first time.  I can get it in and get it opens up pretty well on it's own.  It is comfortable (for the most part--except I feel the stem sometimes), but when time to rinse it out, it has soooo much suction that it takes me a really long time.  The first time, I had to pull with everything I had and it still wouldn't budge.  So I have found that I have to bear down and grab the stem with my left hand, then insert my finger up to the rim and "dig" around to break the suction.  It hurts and I'm not to fond of the mess.  Any suggestions?  

p.s.  I am over 35 and have 1 child so it is the large size cup.