How to handle naysayers without losing yourself

Just the thought of having a meaningful conversation with a pessimist makes me cringe

but on the other hand, not all naysayers mean 'harm'. The major issue I have with people who only give negative feedback without anything positive/encouraging to say is that the intent may be to belittle someone. Having a naysayer as a friend may not necessarily mean that friend is bad as long as you are able to recognize the value of the friendship I mean, no one is perfect. There are various ways to avoid being belittled by a pessimist.

- Be mentally prepared for whatever they have to say.

- Don't ask them if possible.

- Focus on how much you have achieved.

- Remind yourself of that positive feedback that motivates you. 

- Ask for a second opinion from someone else.

- See the positive in the negative statements.

How would you handle a pessimist?