If your partner cannot handle the responsibility of having his sons 50/50, to where he is putting the responsibility on you, he needs to make a change. Even if you only have them on weekends, they are not your responsibility.

Frankly, I would not stay in a living situation in which my kid and I were scared and anxious. You both deserve better and you should not have to put aside your plans to go to school.

I am not hearing much about what dad is doing.  Is the boy with ADHD being treated?  Is the treatment working?  If not, what does dad say?

His kids are not your responsibility, your kids are. Take whatever steps you need to to ensure he takes full responsibility for his. Not your problem. 

For the sake of your son, end this relationship. I read your bio, and you are supporting this man and his kid both financially and emotionally. There is no reason you need to live like this. Why should your son live in fear? You do not need this man and it sounds like he is using you. If you can't do it on your own, please seek out some therapy to help yourself understand why you think you don't deserve better.

What am I getting out of this relationship??  Seams like nothing but having a mental breakdown.  What I can understand.

Both your BF and there BM are dumping these kids on you because they don't want to care for them.  Your BF either stays home with his kids or finds care for them outside your home.  Nobody asked you if they should have kids, they did that themselves. Now they should take care of the kids by themselves 

Your bio says you are a nurse and your son has health issues. So you KNOW stress and anxiety can impact his health. Take a look at how you're living -- are you sacrificing your son's childhood and security for an immature man and his kids? I know many nurses, and each and every one is a helper -- kind and generous, sometimes to a fault. I think your BF is taking advantage of you.

What is your BF doing to lessen the stress, and relieve the burden from you? Anything? If so, is it enough? Do you feel like an equal partner? Or are you picking up his slack because it's easier than fighting with him, and doing it yourself gets better results than insisting he be responsible for his own stuff?

Believe me, I am a fixer, so I totally get how taking on someone else's responsibilities makes things easier -- until the resentment and exhaustion set in. I've done it over and over again, including with my now husband. At first, you think you are helping out someone who will eventually catch on and pull his own weight. But as long as you are willing to do his work, he will be willing to let you. I reached a point with my DH that he was either going to grow up and be my partner, or he'd be living elsewhere. He stepped up and our relationship is MUCH healthier all the way around.

Figure out your boundaries. What would he do with his kids if you weren't in the picture? Take yourself out of the Caretaker of Everybody role for your own sanity and for your son.

Read what you have written.  You're thinking of quoting school - allowing for son to be in a bad situation- and wearing yourself out- for a crappy relationship with a man who only takes.  Wake up- you are the common denominator- go find a better life for you and your boy.

I didn't have to get further than the fact that his kid scares your 8 year old son to say you should end this relationship. It's one thing for you, an adult who can choose to put up with his kids, to be in this hellish situation. It's unconscionable to force your son to live with your fiance's kids and be frightened, put up with meltdowns and inappropriate behavior, and have a mother who is stressed and anxious. No man is worth that.

• His lack of parenting is making you late for work - you could lose your job.
• His lack of parenting is making you anxious 50% of the time while they are not there and scared the other 50% of the time when they are there.
• His lack of parenting is making you think of opting out of preparing your future. 
• His lack of parenting is causing your son to live in fear.
• His lack of parenting is aggravating your son's health conditions.

What can this guy (who you referred to as being immature in your bio) offer you to make up for even a fraction of the above? IF the house is yours, kick them out/tell them they're leaving. If the house is his, find yourself another place to live. Keep dating him if you so choose but don't live with him and his ferals kids.

You deserve so much more than this.

Please leave. You are teaching your child to accept abuse. And you are accepting it for yourself.

Also, please seek to understand why you accept this for yourself (therapy, self/past reflection, whatever works for you, hell PM me if you need someone to talk about it). If you accepted it this time, chances are you will in your next relationship unless you can figure out the why and adjust yourself.  

You and your child are worth more than this relationship is giving you both.