Reusing passwords across multiple sites is very problematic as a password exposure on one site leads to a password exposure on all of your accounts that used the same password. What you are proposing seems better than using a static password across multiple sites, but it is still rather predictable. If someone discovers one of your passwords they can likely guess many of your other passwords. No matter how careful you are with your passwords, they will be discovered. Sites get hacked and password lists are published.
The only way to ensure password safety is to use unique random passwords that have a provably large entropy (a measure of randomness). This answerThis answer discusses randomness as related to password generation.