Well, if you made a patreon for just donations... then people who want to give you a bit of money will give you a bit of money.

im worried i might give out the demands and also im doing commissions already would that mean i can't do it

On a serious note...
If you open up for a patreon for donations only, you aren't showing you can't do anything. You are simply getting some extra money from people who WANT to give you a bit of extra money. All they generally want to see is some WIP of what you are doing as a reward (unless the commission is private).

You just need to be clear that the donations are just that. Donations. If people want to, they will give freely.