i also prefer Tunnelier (Bitvise) It's has SFTP Client, too
Hijacking someone thread to post your preferred SSH client, retardness.
Anyway, i can see the VPS is from vps.me which is not very reliable and they also have lot of restriction like you must login every 24hours on root or they'll suspend your account. Check if the vps is down and try to login with the IPv6 gaven to you.
Btw, they also have a forum so i think this is not the best place to solve your problems.