It took too much to conjure a conversation... how can this work???

I think I've made a mistake... at least part of me feels that way... I feel it takes too much effort to make it work... I'm a lazy person and I'd rather be in a relationship where it just fit just nicely instead of pushing hard to make it fit.. I don't know... I mean.. if it is worth it, then you'd do everything to make it fit... but sometimes it is just too much of a hassle to make it fit... I know I have been sooo wrong so many times in the past... but I just don't feel it this time around... I don't want to be in a relationship where I feel forced to be in it... it is bad for both physical and mental health... should I give it another chance even when I don't think it'll work ? I rather not waste any of our time trying to fix an impossible equation...

Now, how do I tell her???... I have never initiated a break up before... not because all my relationship before this works well... most of it never got off the ground... and those, which had potential ended prematurely... usually because of my takutness to confess or the moment has just passed ( I waited too long... usually because I was afraid I am misinterpreting the sign)  and it is fruitless to even try... One ended because I was having another go at another girl ( come on when you're 16 and 2 girls showed interest... you'd want both of them.. it'll make you look cool with your peers.. haha.. too much testosterone lah last time... I lost both in the end... so no win there...)

“The love that lasts the longest is the love that is never returned.”