I think most people will tell you that the pot is too small. Where are you located? It is very hot over most of the U.S. right now, and the heat will make it hard on container plants, especially in smaller pots.

i really cant tell what size the container is but it needs to be fed. (fertilizer)

Thank you for the replies. I am really new to gardening and only started doing it a few months ago. I think I will start off by changing the pot and fertilizing. Can you recommend a fertilizer for me to use?

And I'm sorry, I forgot to say where I'm located. I'm in Northern California. It has been in the mid 80s to 90s recently. I hope that helps with finding out what I should be doing different.

Thanks again.

You'll get 1000 different fertilizer recommendations, too. Everyone has their own way.

I use osmocote in the soil. It is time-release. Floramato is also popular. With either time-release or organic ferts, it is easier to not kill the plant with too much. Liquid chemical fertilizers work just as well, but it is very easy to add too much and hurt the plant. They also tend to accumulate salts in the soil.

Besides the osmocote, I mix in fertilizers every time I water. I use Alaskan Fish (for N), Jamaican Bat Guano (for P), Greensand (for K), and Epsom Salts for Mg. The plants get all of that in one watering, and then the next watering will be just molasses in the water. I alternate back and forth between molasses and the organic fert mixture.

I also try to let my water sit out overnight before I use it so that the chlorine/choloramines evaporates and the water warms up, especially in the spring when it's cool outside. The chlorine in tap water can kill your beneficial bacteria that you're cultivating with the molasses, but it should evaporate out in 12-24 hours.

If your temps are hot like mine right now, keeping the roots cool will be a big challenge. A larger pot helps. So does a white or light colored one. You could put a little straw on the top of the soil. Try to shade the pot from direct sunlight.

You are lucky you are in California, the rest of us are suffering triple digits combined with high humidity.

You probably just need to repot into a 15+ gallon pot and use something like MG for Tomatoes or anything similar
Maybe ad a little Tomato Tone in the potting mix.

Try a Smart Pot of 15+ gallons, larger if the tomato plant is an indeterminate that reaches 8+ feet tall.
Also clip off the lower leaves especially if they are the ones that are "black" and then when you transplant, plant it DEEP, way past where the old soil level was.

Add a couple inches of mulch on top, or maybe add an inch of large vermiculite and cover that with a red plastic sheet as your mulch.

Here is a link that might be useful: Smart Pots

"Maybe add a little Tomato Tone in the potting mix."

Whoops. When I said "Floramato," I meant Tomato Tone. My fault.

I am pretty sure if I put fish juice and molasses in my potting mix that the Ecoterrorist (Squirrels) would dig up everything I have. Probably would call in the raccoon's at night also.