Hi Tammy! Way to go on hitting the gym. You said once you lost some weight you might have more confidence to go to the gym, etc. but I dunno, no matter what we look like on the outside, if it's something we haven't done in a while, it takes a few visits to get in your comfort zone. And you will.
A really bad thing I do is compare myself to others. Particularly stupid for a 45 year old woman to compare herself to 18 year olds whose brains are still pumping the youth growth hormone, for pete's sake. So I try to go to the gym thinking very selfishly...as though I am the only person who matters while there. I'm not there to compete with 18 year old university students, I'm not there to look attractive to any man my age, I'm not there to judge myself, I'm simply there to do something that's good for ME. I need to have little mental talks with myself about this stuff. All athletes will tell you, they need to do positive self-talk while working out. Coaches actually train them on this self-talk. So you might find one to three statements that you could chant in your mind a few times while going to the gym, and while at the gym.
I don't know why songs are occuring to me so much but when you talked about TOM I thought of David Bowie's Space Oddysey:
Ground control to major Tom
Ground control to major Tom
Take your protein pills and put your helmet on...