Ok thank you,
As long as there is not more than a teaspoon of blood or he is vomiting up digested blood which looks like coffee grounds. Because that would indicate a serious bleed.
And pale gum color would be a signs of a serious bleed as well.
Sometimes when they vomit the tiny blood vessels in the esophagus rupture and that causes a tiny amount of blood in the vomit.
I would start with giving him a stomach acid reducer.
Use 1/4 of a human over the counter Pepcid AC tablet every 12 hours.
You can pop it down his throat and chase it with a few drops of water so he swallows.
Or, you can put it in a treat.
Or, you can crush it and give it in a syringe or eye dropper with water.
I would not feed him, except for a treat to get the Pepcid AC in him, until he has not vomited for 8 hours.
Then offer him small bites of chicken for a day which is easier to digest than cat food.
If he does well with that put him back on his regular diet.
Does that help? Do you have any additional questions?