Well it sounds like you have found the condom for you - Magnum XL!!
Condoms are all pretty much the same length it's the width (girth) that matters - too tight and you feel uncomfortable and want to take the damn thing off (don't of course) too lose and you stress about it slipping off. Neither make you feel very sexy and able to enjoy the sex you are trying to have!!! (if you want to know more, about condom girth - check out each manufacturers websites and ask for a free sample - they want your custom so they will send you some freebies).
Try and find a decent water based lubricant, this will help with penetration and help protect the condom from being damaged, this is really important for gay men who go to a very dry place ( I know you are straight 95LSv ) but women can be dry sometimes too. Actually, if a women is dry, it means she is not ready for sex yet and some more foreplay is required - or give her some respect and don't have penetrative sex - but say "no" gently - be kind about it. You won't want to ruin your chances of trying again another day!!!!! similar for gay men too about anal penetration
Don't forget to put your condom on before any release of precum or cum as this will risk pregnancy or an STI, put some water based lube on the outside of the condom (NEVER put lube on your cock and then put on the condom as the condom WILL slip off). If you are having a marathon session, don't forget to put on a new condom every 20 mins, thus ensuring that you are using a condom in best condition.
Hope that helps
Brinz