This will be your magic tool to give you the results you are looking for.
ReRead your submission and think of it as someone else's...would you say this person sees themselve in a positive way or a negative way?
The best friend and worst enemy you will have in your life is YOU! And you decide whether yiu trust and love yourself or whether you will continue to judge yourself. To make it clear, you are making it harder on yourself by telling yourself that you are not good enough, or that you used to be "better" look at you! You said yourself that you've been taking care of a sick family member. That is beautiful, that is strong, that is caring and that is love. Maybe you haven't felt enough support or attention but you are an angel to your mom. All that love and care you have provided for her means you have that much in you to love and care for yourself!
Start loving yourself. Make sure you are getting enough rest, sleeping properly, eating regularly, and giving yourself time off when you need it. Go out with friends, remind yourself what you enjoyed about your time in high school. You'll find it has a lot more to do with what you were doing then whet you looked like. What activities do you enjoy or look interesting to you? Take a class!! Go out with friends or find a gym or recreation group around you that partaken in those activities.
Make a list for yourself of all the things you'd like to do and share it with people who will support you, not those who may not. Do it for you! Love youself and take care of yourself, like you do your mom. You're the only one who can do that. Invest in a friend to take your mind off of things, look into hiring a care person to help or 'nanny' to help with any errands or tasks that may help unload your schedule a little bit. Go out for a date, if you're single, or just go out dancing. Find the passion in you that excites you that moves you inspires you, he'll blast some good music in your car or pour yourself a small glass of wine on the weekend. Find a plethora of tools or 'crayons' you can pull out to help color your day or week a little brighter