i have a problem...

hey guys,
I haven't posted on here in a while, think the last time i wrote on here was a couple of weeks ago when I was having a really bad time(crisis team came out to see me and so on.) I have started to get better with the help of medication and at the moment seeing the home treatment team. However still have very dark days and have noticed at first I had improved anxiety wise but still have some issues. One of those is being around my partners children. I have not had much contact since about a month ago as was in to much of a state to see them, last weekend met up on the Saturday with my mum and then weds eve when they came round after school to sleep. We are going to have them on the Monday after school to sleep and I wasn't aware of this till a couple of hours ago. I just now feel completed panicked,I have always had a good relationship with the girls who are 5 and 7 and although at first I did have anxiety issues around them I have known them for 3 years now and have had very little anxiety issues till now. Just feel stupid and dont understand why my anxiety is honing in on my relationship with them. Feel so stressed and feel like it is really holding back my recovery from depression/anxiety and don't know how to conquer it.
Just feel pretty miserable.
Thanks for listening to my rambles.

what is you get anxious about ? Is there any particular thing ?

that's the thing I have no idea! I don't know why I get so anxious...the last two and a half years I have very little anxiety surrounding the children, I think sometimes I worry I cant handle them or that when they get upset I might or stupid things like that. I think sometimes what if I cant handle it? and then instead of just treating the thoughts as just a reaction to panic and not my true emotions i run away with it and have panic attacks.Its like i cant think rationally at all.