First of all, how "tight" you are is a function of your PC muscles. You need to relax them for insertion and especially for removal, then you can go back to holding them as tight as you usually do (quote Kuradi8). ;) For me, relaxing my muscles is a lot like pushing for a wee or bowel movement : this make my opening more... open.

The cups you have are fairly soft, especially the Meluna, so they need a little help popping open, but most of all they need space and air (which is the same thing) so they can expand. There's no way they can do that by themselves if your muscles are clenching them. Another thing that's helped me at first is to lie on my back, in my bedroom, knees slpayed, and if you can, lifting your butt up slightly. This also helps keep things open. My favourite fold is half diamond : it's tiny and intricate and hard to hold together, which is good because it pops open almost at once, and if not, since the first step to the fold is to pull the rim downwards, you can push that piece of rim inside and help it unfold that way, with a simple poke. You could also try the triangle fold, which can be unfolded manually, and perhaps the labia fold too.

What also helps a ton is to run the cup under cold water before, place one hole at the center of the fold, and face the folded part towards your anus, which is where the vagina is softer. Also, inserting a finger there next to the cup to create an air channel. Have you read this post ? http://menstrual-cups.livejournal.com/2618390.html#cutid1

And because your cups are also fairly short compared to other models, you'll need to bear down (birth or poop the cup out) until it is within reach, get a hold of it, and possibly try to insert a finger between the cup and your vagina to break the suction. It's a lot more effective with soft cups than pinching and pulling. Good luck, you'll get better at this, I promise !

agreeing with Julie's advice! you might need to unfold the cup manually once it's inside (not uncommon with soft cups) and try to cold water trick and read the FAQ post on getting cups to pop open.

once you get through the learning curve (which might take you a few cycles) you can always sell the cup you don't use anymore/doesn't fit you etc on http://mc-sales.livejournal.com/ :)

for removal you need to 'bear down' hard with your muscles, pretend that you are giving birth to the cup! until you can get a hold on the stem. then, slowly pull and wiggle the cup side to side to break the seal and squeeze the base with your other hand. you can also press on side of the cup inwards for removal so it isn't as big coming out (hot dog in a bun method your finger being the hot dog!). I suggest letting one corner out first at a diagonal and the the other corner to minimise discomfort.

The main advice is the RELAX your entire body for insertion and removal. cups require pracrice, patience and relaxation but you'll get there! :)

everyone has these difficulties in the beginning but once you get through the learning curve you'll be giving advice to other fist time users :) you can do it!