Before few month I use to talk to a lot of girl but now i'm to shy again
what to do ? I wanna come and flirt again how to make it work ?

What are you doing differently than you did before? Why the sudden shyness? is there something that has triggered it specifically?? If so that might be part of the answer of how to get over it.

Other ways can be to go out and talk to loads of people, just engage people in small talk, men, women, doesnt matter just go up to someone smile and say "hey how are you, this weather is amazing" for example! The more you talk to strangers the more you can accept that its not a big thing, and just get over that AA.

What are you afraid of if you go and talk to a girl (or anyone infact)? If you go hey nice weather isnt it? Whats the worst that can happen? Its doubtful theyll tell you to go fuck yourself as most people are ordinary, polite and havent been bought up to be rude! The worst that will happen is theyll look at you funny, answer you and maybe just excuse themselves!

Just go for it dude

You need to overcome shyness for good. Try to do a public speaking course of some sort.

You have to push through it with full force. There's no other way.

I have social anxiety and I know where you're coming from here. You just have to force yourself, even with the awkward feelings and such, once you push yourself, you will feel more comfortable. Did you take a break from talking to girls for a while? After I was done with high school, I didn't do much afterwards in terms of social interactions, and so I lost my composure in social situations.

Once you get back out there, things will change, trust me.