Ouch. Needs help alright. You're in luck however, there are some good lemon growers here to help you. (I'm not one of them tho).

Is that all the light the tree receives? How big it the container? Perhaps you have root problems. What kind of potting mix is it in? How often do you water it? More information like that will help others here to help you.

I'm no expert, but If that were my tree (and it has root problems), I'd cut off those dead limbs, take it out of the pot, inspect the roots, put it in a little bigger pot with fresh good draining potting mix, feed it, let it heal in a sunny spot. Next year it may look like a different tree.

Good luck to you...

Did you just move it indoors? Please post a pic of the entire tree.

Was it outside for the summer? Need more info on what care you have provided it.

Pick the fruit and eat it. It is ripe enough and its removal will be very good for the tree.

6b Steve

You cannot let the let the water stand in the tray at the bottom of the pot after watering. Plus quantity of light may be an issue too.

I can post another picture later once I get home. I live in the Dallas area in an apt so putting it outside is not an option at this time. I have had it since March and it is in a window facing southern exposure in citrus soil. (Today is cloudy but it typically gets sunshine, I have even rotated it a few times) I have wondered if I am watering it properly as no where online does it say an exact amount. I do about 32 oz every 1 to 2 weeks depending on how the soil feels. My fiance's parents have offered to take it in their backyard but I am nervous the sudden outside exposure will kill it off and temps do hover above freezing for a few weeks in the winter here. Thoughts?

Good news. Your stems are green and therefore are generating food for your tree.

Take the ties off it. They look tight!

It looks like all of the above mentioned problems plus research the 511 mix on the forum and repot it. You water only once the tree is dry in the new mix and let the water drain out and then repeat. Also what is your fertilizer schedule?