my wordpress site is hosted on godaddy, using flatsome theme, 7 plugin (including img-lazy load & woocomerce). i have use free cloudflare cdn, but still my site need 13+ seconds to load. i have checked it on gtmetrics, and it says i have too much DOM (4,5k+)
You are using Woocommerce which starts a session for every visitor to your site. This limits Cloudflare's cache performance since each unique session needs to be handled individually. That's how things like the shopping cart work.
Woocommerce added the ability to store this session data in object cache rather than the database (memcached/Redis/etc).
I'm not familiar with GoDaddy's hosting since I personally don't recommend that company, but they should have object cache storage of some sort available. It's just a matter of you configuring WordPress and Woocommerce to use this cache.
That should help things a bit.