Advice / looking for help

Hi I'm new to the app but I'm looking for some help. I'm in a relationship with my girlfriend for 4 years now and recently we've had more down days than up days and not really feeling close. There has been alot of big changes in our lives recently and neither one of us deal with change well at all. It has put alot of stress on our relationship and it seems like we fight about everything. I have an extremely hard time expressing my feelings but I try really hard to express them to her (that in its self causes stress) and hate confrontation. Yesterday was a rough day for us. We had made plans to go trick or treating with my sister and her two kids and then come back to our house to have supper. In the morning she came to me saying that she had to run to help a friend that lived a few hours away but said that she would be back before our plans. She had invited me to ride with but I decided to stay home cause I wanted to make sure that I was home to keep our plans. Well as the day went on things took longer than she thought they would and she ended up not making it back in time. While she was gone she ended up running into a different old friend and found out that another old friend that she was really close to had passed away and she took that hard ( I understood that she couldn't control that and that it affected her ability to get home in time). Well she finely made it home and we caught up and talked about what had went on through out the day. Then came bed time and that's when everything went horribly. Bedtime is a struggle every night. She suffers from severe sleep anxiety from things that have happened in her childhood. Which I have been very understanding about and have tried to help make it easier on her. Usually when it comes to bedtime I ask her if she is ready to go to bed and crawling in together and her response is no I'm not ready (even though she is falling asleep already on the couch). It ends in one of two ways either in an argument (it's like a switch is flipped in her) or me just going to bed hurt cause she ends up passing out on the couch. Well last night I decided to try something different cause I knew she had a very rough day and needed the sleep and I didn't want it to end in an argument. So bedtime came and she started falling asleep on the couch and instead of asking if she was ready for bed I asked her to get her feet up and get comfortable on the couch and I was going to tuck her in there. That was the wrong thing to do cause it ended in an argument anyways. She said that I hurt her and wasn't sensitive about her having a rough day emotionally with learning about in old friend passing away. Which I do see where she is coming from but I didn't do it to hurt her I was doing it to help her but she didn't see it that way. I tried to explain it to her but it didn't help. I apologized for hurting her. I feel like no matter what I do it's the wrong thing. Anyways I'm just wondering if anyone has any advice for me and how to handle it differently so that it doesn't hurt either one of us get back to being close and not arguing about everything?