STS Positive Polarity

[Infinite]

I just don't have feelings for people.
I only have emotions for animals.

You are just blocked. Working on yourself can one day open you up more and more and start seeing reality in a completely new way.

I can't force myself to love others.

No. This is the good and difficult part of the STO path. You can't use willpower to love others. But you can use it to seek for that love. So don't think in terms of forcing or not, but trying to understand what that love means.

Am I doomed to go to 4D negative because I don't like people?

No. You would have to be a lot more negative to have a minimal chance of going to a negative 4D planet.

Also, I do not like the idea of a social memory complex.
Mind melding with others would be hell for me.

Yes, one more feature of possible blockages. The inability to open up to others. Don't worry about it now. Meditate a lot and try to find a path. When you're ready, look back and realize that your fears never made sense and that you just needed a prospective bride to finally live the real life. Evolution is about a transformation, a new and elevated being is born and the third density ego, the one who sees everything from a limited perspective, becomes the past.