How do I push myself and keep going?

I am 25 and I do not know what to do and how to push myself in the situation that I am currently in. There have been constant setbacks in my life, one after another. Mental health has been in literal trenches for more than 4 years and it has only gotten worse with time.

I have been chubby all my life but now I am overweight....borderline obese. At least once in my life I want to know what it's like to look good and be healthy. But I am unable to focus. My parents want me to get married ASAP and it's all they talk about. I convince myself to be happy, to give myself one shot, to workout etc...but every other day I hear something and my heart just drops and I lose will to do anything.

I don't know if anyone will relate to it. But I am unable to do anything when I am constantly surrounded by uncertainty. They keep on talking about me to my relatives about how fat I am, how I need to lose weight, what a disappointment I am etc. It's constantly just about marriage...and these talks are exhausting. I want to tell them I don't feel ready, please give me atleast two months. I want to switch jobs and look at other career prospects...i want to solely focus on myself. But they aren't the kind to listen. Whenever I mention about it there is a huge argument in my house.

What do I do....amidst all this chaos I am runing my body, ruining my mental peace and ruining my youth. I have started to have so many body issues...and I know I can't and shouldn't put off working out. But I keep on losing the will. Having to constantly hear about how I am too old now, how fat I am etc just ruins my mood.

If anyone has been in a similar situation what did you do, how did you still manage to show up and convince yourself to eat well, exercise etc.