I had four kids, I have stretch marks... I used to be really self conscious about them, but they have faded and are not as noticeable now... men I've been with used to kiss them, and tell me not to worry- they were a part of what made me into the wonderful woman I am... and after having several of those experiences... I don't even worry about them anymore.
As for cellulite, even mega-stars have some cellulite... I'm also fortunate that I don't have nearly anything at all... but age will kick your ass. LOL!
As for sexy... the most sexy thing you can possess... is self confidence. Truly... when you love yourself enough to be proud of who you are, stretch marks, cellulite and all... you'll find it really doesn't matter to most men... and in fact, the things we're toughest on ourselves for... many men actually like...
That's just my experiences...