Hello. I understand you want to please your partner, but there are some things for each person that they just aren't able to do, even if they want to.
Squirting is over rated in my opinion. It is also difficult, sometimes impossible for some women to achieve. There also seems to be a connection between trying hard to achieve squirting and being unable to. Simply going along with no pressure on trying to squirt is best. Perhaps trying sex toys to help along with squirting may help. Unfortunately, I haven't found any sure way of succeeding. I have squirted a few times, using sex toys, but I actually was completely unaware of it until I gave up trying to reach orgasm and finding a big wet streak on the bed sheet. It is a different experience for different women, so you can keep trying, but don't revolve your sex life and mind around squirting. If it does happen, then great, but just remember that not every woman can succeed, same as not all women can get a g-spot orgasm, or orgasm from penetration. I'd suggest you let your partner know that too, so he understands.
As for the being unable to perform urinating on your partner, is it possible that its just because you are not used to peeing when you are not on the toilet, let alone on another person. Its not that you think its disguisting or anything, its just that its not something you have done before and there is a mental block, like, don't pee on the floor!
Have you tried doing this in the bathroom? If you have a bath, this may be the best place. Obviously you don't want a nasty mess to clean up afterwards, and the bath is the easiest place to do it. The bathroom will feel less alien to do what you would normally do in there (having a pee). You could also try having a pee in the bath when you need to go before you try to do it for your partner. Then you only have one mental block of urinating on a person, rather than the blocks of being in the wrong place, the backthought of cleaning up afterwards, not doing it where you would normally do it and feeling more comfortable with peeing in that place before.
I hope at least some of this makes sense. I should be asleep right now!
Good luck.