Hi Bethrags, sorry to hear about your T being off sick so much, that would trigger so many bad feelings for me too.
I noticed you already know your pattern of not being able to trust or rely on people. These usually come from when we were small and had no choice in what was happening to us? This is true for me also.
But now you do have a choice with what happens to you, you can change things and set your boundaries and find someone who can help you. I like your plan of cancelling sessions until September. Maybe this would give you some breathing space to not feel let down all month? Maybe it will become clearer what the next step is, if it's time to look for someone that can really be there for you. Some good ideas come when you make the space for yourself.