Hello.
I'm very new to gardening. My tomato leaves started to turn yellow at the top. I googled and think it's a virus. My plants are growing in a good soil+compost, have enough light and water. I also add plant food every week.
One week ago I added Epsom salt to my tomatoes to help them turn green again, but it didnt work.
Thank you.

You are over-fertilizing. Container plants take a lot less fertilizer than in ground plants and even in ground, once a week would be too much. Potting soil is fortified (fertilizer is added to the soil) already. Epsom salts did not help your situation.

Flush the soil and don't fertilize anymore. Hopefully, your tomato will pull out of this.

Being new to gardening you are micro managing. You are simply worrying too much. Relax.
Give them 35 hours of sun max! Otherwise keep them bright.
When they grow rapidly as young plants, they often produce yellow -
green foliage due to rapid cell expansion. The good green color, nitrogen based, will catch up. Just when you see the first blossoms forming is the time I fertilize. They sell a 'tomato blended fertilizer' which works well. I have also used Miracle Grow in the yellow and green box.

DaisyI, BigBill
Thank you!!

You are most welcome!
Good luck! I can taste those tomatoes from here.