This is a first for me as I've never had to ask anyone for this type of help before.
Exactly what type of help are you looking for?
I'm planning on leaving my sick lover.
You should always be able to ask for help, even if you've never done it in the past. You shouldn't feel embarrassed, especially with something as delicate and important as leaving a lover who is sick, which in my opinion is something you shouldn't do. Sticking with someone through the hard times builds character and creates an even stronger relationship.
I understand, but I don't want to be in this relationship. And I think this is urgent because I'm not feeling well myself and I'll be out of a job soon.
I genuinely don't believe that ending the relationship is going to solve these issues and you shouldn't abandon people when they're struggling, but it's good that you asked for help. If you must, make sure you end things with compassion and be truly mindful of their feelings and wellbeing. You can still be supportive even if you are no longer a couple.