I know how she feels than since my own extreme stress lately has been a big cause of my problems. I think it would have been more accurate to say I was disconnected rather than having trouble bonding.
Stress could be a major factor in your lack of connected feelings. IME people have a harder time doing anything with the 'lighter' emotions when under stress.
I'm bad for this one, stress makes me want to 1) buckle down and just get through it, which leads to me ignoring my SO more than I should 2) pick up a book and read for 8-10 hours straight....Yay coping mechanisms, lol.
You may find that as your stress reduces (here's hoping it does) you'll have more emotional energy left for bonding with Sera. To give you an idea of what I mean check out this article: But You Dont Look Sick? support for those with invisible illness or chronic illness The Spoon Theory written by Christine Miserandino - But You Dont Look Sick? support for those with invisible illness or chronic illness
I know it's designed for illnesses etc, but I think it works for stress too.
Things have been mostly ok thankfully though sometimes I have to catch myself.
The fact that you're aware of it is actually a bonus in my books. It's much harder to address and issue if you aren't even aware of it happening.
Like her sister she is loving she just gets under my skin sometimes it's not her fault I've been really disconnected as of late. I mean lately I was having periods where I basically blanked out when at University and by the time my mind came back a few minutes had passed.
There's two points I want to address to this comment, so bear with me as I try to work it out in a coherent fashion...
It's a simple fact that beings bond easier with some other personalities than others. We have four cats, and while I love them all dearly, I have a stronger bond with Doran and Jitzu. I make a conscious effort not to play favorites, but I'm also aware that sometimes it IS a conscious effort. It works out well, since my SO is closer to Muffin and Torri, so we have balance, but it can lead to issues when we disagree on which kitty is the problem causer at that moment. A side effect of this closer bonding is that I have more patience for Doran and Jitzu's foibles than my SO does, and vice versa. So when Doran starts up his spraying in the spring my SO reaches boiling point WAY before I do - leading to problems we have to work through.
Secondly, I'm a big fan of the saying 'you get out what you put in'. In this instance what I mean by that is that the more affection you spend on Sera the more you will feel for her. When I'm working with a client who has been dealing with behavioral problems in their pets one of the things I always tell them to do is pick something fun and silly to do with the pet. In order to have a bond you need to work on it, you need to find ways to have a special connection with Sera that maybe you don't have with Tsuki.
I do this by having special cuddles with only Jitzu sometimes, Torri is the only cat allowed in our room - and therefore the only one I sleep with regularly, Doran...is the one I bond to easiest as he's my cuddle-baby, and Muffin gets to do extra training and playing (which also helps curb his naughtiness, as a bonus).
Pick something you will only do with Sera, what it is doesn't matter and it doesn't need to be completely exclusive, but make a point of spending time only and specifically with her. Put Tsuki away and focus on spending some time with Sera. You might be surprised what a difference it makes.
It's funny though if I get annoyed with her she will cling to me well if anyone does she will haha.
THAT is a fairly common behavior pattern that will build up to attention seeking behavior. Generally these are behaviors that are annoying, irritating, and push our buttons. This happens because the animal figures out that you will ALWAYS respond if you catch them doing X thing. (Scratching the couch, bullying another animal, biting you, pushing over the TV, etc).
The way to stop this is to ignore her until she does something you like, and that can be as simple as sitting/standing nearby and not yelling at you - at first. When she stops fussing you praise her and give her some attention, then follow that up with a fun toy she can play with by herself. This will teach her good things happen to patient and quiet kitties.